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1.  Diet Type and Changes in Food Cravings following Weight Loss: Findings from the POUNDS LOST Trial 
Eating and weight disorders : EWD  2012;17(2):e101-e108.
Few well-controlled trials have evaluated the effects that macronutrient composition has on changes in food cravings during weight loss treatment. The present study, which was part of the POUNDS LOST trial, investigated whether the fat and protein content of four different diets affected changes in specific food cravings in overweight and obese adults. A sample of 811 adults were recruited across two clinical sites, and each participant was randomly assigned to one of four macronutrient prescriptions: (1) Low fat (20% of energy), average protein (15% of energy); (2) Moderate fat (40%), average protein (15%); (3) Low fat (20%), high protein (25%); (4) Moderate fat (40%), high protein (25%). With few exceptions, the type of diet that participants were assigned did not differentially affect changes in specific food cravings. Participants assigned to the high fat diets, however, had reduced cravings for carbohydrates at Month12 (p< .05) and fruits and vegetables at Month 24. Also, participants assigned to high protein diets had increased cravings for sweets at Month 6 (p< .05). Participants in all four dietary conditions reported significant reductions in food cravings for specific types of foods (i.e., high fat foods, fast food fats, sweets, and carbohydrates/starches; all ps< .05). Cravings for fruits and vegetables, however, were increased at Month 24 (p< .05). Calorically restricted diets (regardless of their macronutrient composition) yielded significant reductions in cravings for fats, sweets, and starches whereas cravings for fruits and vegetables were increased.
PMCID: PMC4189179  PMID: 23010779
Macronutrient composition; Caloric restriction; Food type; Fat; Carbohydrate; Protein
2.  Obesity and Diabetes as Accelerators of Functional Decline; Can Lifestyle Interventions Maintain Functional Status in High Risk Older Adults? 
Experimental gerontology  2013;48(9):10.1016/j.exger.2013.06.007.
Obesity and diabetes are known risk factors for the development of physical disability among older adults. With the number of seniors with these conditions rising worldwide, the prevention and treatment of physical disability in these persons has become a major public health challenge. Sarcopenia, the progressive loss of muscle mass and strength, has been identified as a common pathway associated with the initial onset and progression of physical disability among older adults. A growing body of evidence suggests that metabolic dysregulation associated with obesity and diabetes accelerates the progression of sarcopenia, and subsequently functional decline in older adults. The focus of this brief review is on the contributions of obesity and diabetes in accelerating sarcopenia and functional decline among older adults. We also briefly discuss the underexplored interaction between obesity and diabetes that may further accelerate sarcopenia and place obese older adults with diabetes at particularly high risk of disability. Finally, we review findings from studies that have specifically tested the efficacy of lifestyle-based interventions in maintaining the functional status of older persons with obesity and/or diabetes.
PMCID: PMC3817488  PMID: 23832077
Physical Function; Obesity; Diabetes; Aging
3.  Can Non-Nutritive Sweeteners Enhance Outcomes of Weight Loss Interventions? 
Obesity (Silver Spring, Md.)  2014;22(6):1413-1414.
PMCID: PMC4147372  PMID: 24862169
4.  How Much Walking Is Needed To Improve Cardiorespiratory Fitness? An Examination of the 2007 ACSM/AHA Physical Activity Recommendations 
The 2007 American College of Sports Medicine (ACSM) and the American Heart Association (AHA) physical activity guidelines recommend adults engage in either 150 minutes of moderate intensity or 60 minutes of vigorous intensity physical activity per week to derive health benefits.
In a 6-month clinical trial, we examined whether walking programs of moderate (leisurely-paced) and vigorous (fast-paced) intensity produced improvements in cardiorespiratory fitness as predicted by the ACSM/AHA guidelines.
Participants (N = 155) were instructed to walk 30 minutes per day on 5 or more days per week, at either a moderate or vigorous intensity level (45–55% or 65–75% of maximum heart rate reserve [HRres ], respectively). Within each condition, we categorized participants based on their mean weekly amounts of exercise as reflected in written self-monitoring logs. Fitness was assessed by a maximal graded exercise test at pre- and post-treatment. This trial was conducted in Gainesville, FL between 1999 and 2003.
Mean minutes of walking were related to changes in cardiorespiratory fitness in the vigorous (r = .47; p = < .001) but not moderate intensity condition (r = .07; p = .52). Within the vigorous intensity condition, significantly greater improvements in fitness were achieved by participants with high and medium amounts of accumulated exercise compared with those with low amounts of exercise.
Clinically meaningful improvements in cardiorespiratory fitness were observed in participants who walked a minimum of 60 minutes per week at a fast-pace but not those who walked at a leisurely-pace. These findings support the 2007 ACSM/AHA physical activity recommendations regarding vigorous, but not moderate, intensity physical activity for cardiorespiratory fitness.
PMCID: PMC4126169  PMID: 21699118
walking; exercise intensity; intensity; fitness; physical activity; physical activity guidelines
5.  Effect of Dietary Restriction and Exercise on Lower Extremity Tissue Compartments in Obese, Older Women: A Pilot Study 
Accumulating evidence suggests that both dietary restriction and exercise (DR + E) should be incorporated in weight loss interventions to treat obese, older adults. However, more information is needed on the effects to lower extremity tissue composition—an important consideration for preserving mobility in older adults.
Twenty-seven sedentary women (body mass index: 36.3±5.4kg/m2; age: 63.6±5.6 yrs) were randomly assigned to 6 months of DR + E or a health education control group. Thigh and calf muscle, subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) size were determined using magnetic resonance imaging. Physical function was measured using a long-distance corridor walk and knee extension strength.
Compared with control, DR + E significantly reduced body mass (-6.6±3.7kg vs control: -0.05±3.5kg; p < .01). Thigh and calf muscle volumes responded similarly between groups. Within the DR + E group, adipose tissue was reduced more in the thigh than in the calf (p < .04). Knee extension strength was unaltered by DR + E, but a trend toward increased walking speed was observed in the DR + E group (p = .09). Post hoc analyses showed that reductions in SAT and IMAT within the calf, but not the thigh, were associated with faster walking speed achieved with DR + E (SAT: r = -0.62; p = .01; IMAT: r = -0.62; p = .01).
DR + E preserved lower extremity muscle size and function and reduced regional lower extremity adipose tissue. Although the magnitude of reduction in adipose tissue was greater in the thigh than the calf region, post hoc analyses demonstrated that reductions in calf SAT and IMAT were associated with positive adaptations in physical function.
PMCID: PMC4158399  PMID: 23682155
Body composition; Weight loss; Obesity; Aging; Disability.
6.  Caloric Restriction to Moderate Senescence: Mechanisms and Clinical Utility 
As life expectancy in the United States continues to increase, the maintenance of physical independence among older Americans has emerged as a major clinical and public health priority. Therefore, there is an urgent need to identify interventions that can maintain or enhance cognitive and physical function with the goal of preventing or delaying the onset of disability. To date, caloric restriction (CR) is the only method that has been consistently found to increase lifespan and delay the onset of age-associated diseases such as cancer and diabetes across multiple species. The promise of calorie restriction as an intervention to improve health and/or maintain function in humans, however, only holds if individuals are able to adhere to this intervention over the long-term. Unfortunately, long-term adherence to CR regimens is notoriously poor likely due to complex interactions between behavioral, physiological, psychological, and environmental variables. Thus, a current challenge for both researchers and clinicians is to identify methods that can assist individuals in maintaining CR over the long-term.
PMCID: PMC3899841  PMID: 24466503
Caloric restriction; Aging; adherence; lifestyle; health-span; life-span; body weight; appetite
7.  A randomized trial comparing weight loss treatment delivered in large versus small groups 
Behavioral interventions for obesity are commonly delivered in groups, although the effect of group size on weight loss has not been empirically evaluated. This behavioral weight loss trial compared the 6- and 12-month weight changes associated with interventions delivered in a large group (LG) or small groups (SG).
Obese adults (N = 66; mean age = 50 years; mean BMI = 36.5 kg/m2; 47% African American; 86% women) recruited from a health maintenance organization were randomly assigned to: 1) LG treatment (30 members/group), or 2) SG treatment (12 members/group). Conditions were comparable in frequency and duration of treatment, which included 24 weekly group sessions (months 1–6) followed by six monthly extended care contacts (months 7–12). A mixed effects model with unstructured covariance matrix was applied to analyze the primary outcome of weight change while accounting for baseline weight and dependence among participants’ measurements over time.
SG participants lost significantly more weight than LG participants at Month 6 (−6.5 vs. -3.2 kg; p = 0.03) and Month 12 (−7.0 vs. -1.7 kg; p < 0.002). SG participants reported better treatment engagement and self-monitoring adherence at Months 6 and 12, ps < 0.04, with adherence fully mediating the relationship between group size and weight loss.
Receiving obesity treatment in smaller groups may promote greater weight loss and weight loss maintenance. This effect may be due to improved adherence facilitated by SG interactions. These novel findings suggest that the perceived efficiency of delivering behavioral weight loss treatment to LGs should be balanced against the potentially better outcomes achieved by a SG approach.
PMCID: PMC4180323  PMID: 25249056
Weight loss; Group size; Lifestyle intervention; Randomized trial
8.  The Impact of Behavioral Intervention on Obesity Mediated Declines in Mobility Function: Implications for Longevity 
Journal of Aging Research  2011;2011:392510.
A primary focus of longevity research is to identify prognostic risk factors that can be mediated by early treatment efforts. To date, much of this work has focused on understanding the biological processes that may contribute to aging process and age-related disease conditions. Although such processes are undoubtedly important, no current biological intervention aimed at increasing health and lifespan exists. Interestingly, a close relationship between mobility performance and the aging process has been documented in older adults. For example, recent studies have identified functional status, as assessed by walking speed, as a strong predictor of major health outcomes, including mortality, in older adults. This paper aims to describe the relationship between the comorbidities related to decreased health and lifespan and mobility function in obese, older adults. Concurrently, lifestyle interventions, including diet and exercise, are described as a means to improve mobility function and thereby limit the functional limitations associated with increased mortality.
PMCID: PMC3195552  PMID: 22013527
9.  Effects of a weight loss plus exercise program on physical function in overweight, older women: a randomized controlled trial 
Obesity and a sedentary lifestyle are associated with physical impairments and biologic changes in older adults. Weight loss combined with exercise may reduce inflammation and improve physical functioning in overweight, sedentary, older adults. This study tested whether a weight loss program combined with moderate exercise could improve physical function in obese, older adult women.
Participants (N = 34) were generally healthy, obese, older adult women (age range 55–79 years) with mild to moderate physical impairments (ie, functional limitations). Participants were randomly assigned to one of two groups for 24 weeks: (i) weight loss plus exercise (WL+E; n = 17; mean age = 63.7 years [4.5]) or (ii) educational control (n = 17; mean age = 63.7 [6.7]). In the WL+E group, participants attended a group-based weight management session plus three supervised exercise sessions within their community each week. During exercise sessions, participants engaged in brisk walking and lower-body resistance training of moderate intensity. Participants in the educational control group attended monthly health education lectures on topics relevant to older adults. Outcomes were: (i) body weight, (ii) walking speed (assessed by 400-meter walk test), (iii) the Short Physical Performance Battery (SPPB), and (iv) knee extension isokinetic strength.
Participants randomized to the WL+E group lost significantly more weight than participants in the educational control group (5.95 [0.992] vs 0.23 [0.99] kg; P < 0.01). Additionally, the walking speed of participants in the WL+E group significantly increased compared with that of the control group (reduction in time on the 400-meter walk test = 44 seconds; P < 0.05). Scores on the SPPB improved in both the intervention and educational control groups from pre- to post-test (P < 0.05), with significant differences between groups (P = 0.02). Knee extension strength was maintained in both groups.
Our findings suggest that a lifestyle-based weight loss program consisting of moderate caloric restriction plus moderate exercise can produce significant weight loss and improve physical function while maintaining muscle strength in obese, older adult women with mild to moderate physical impairments.
PMCID: PMC3131984  PMID: 21753869
obesity; weight loss; physical function; oxidative stress; inflammation; walking speed
10.  Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels 
Appetite  2010;55(1):37-43.
Consumption of sugar-sweetened beverages may be one of the dietary causes of metabolic disorders, such as obesity. Therefore, substituting sugar with low-calorie sweeteners may be an efficacious weight management strategy. We tested the effect of preloads containing stevia, aspartame, or sucrose on food intake, satiety, and postprandial glucose and insulin levels. Design: 19 healthy lean (BMI = 20.0 – 24.9) and 12 obese (BMI = 30.0 – 39.9) individuals 18 to 50 years old completed three separate food test days during which they received preloads containing stevia (290 kcal), aspartame (290 kcal), or sucrose (493 kcal) before the lunch and dinner meal. The preload order was balanced, and food intake (kcal) was directly calculated. Hunger and satiety levels were reported before and after meals, and every hour throughout the afternoon. Participants provided blood samples immediately before and 20 minutes after the lunch preload. Despite the caloric difference in preloads (290 vs. 493 kcals), participants did not compensate by eating more at their lunch and dinner meals when they consumed stevia and aspartame versus sucrose in preloads (mean differences in food intake over entire day between sucrose and stevia = 301 kcal, p < .01; aspartame = 330 kcal, p < .01). Self-reported hunger and satiety levels did not differ by condition. Stevia preloads significantly lowered postprandial glucose levels compared to sucrose preloads (p < .01), and postprandial insulin levels compared to both aspartame and sucrose preloads (p < .05). When consuming stevia and aspartame preloads, participants did not compensate by eating more at either their lunch or dinner meal and reported similar levels of satiety compared to when they consumed the higher calorie sucrose preload.
PMCID: PMC2900484  PMID: 20303371
Stevia; Aspartame; Sucrose; Food Intake; Satiety; Hunger; Insulinogenic Index; Insulin Sensitivity
11.  Models of Accelerated Sarcopenia: Critical Pieces for Solving the Puzzle of Age-Related Muscle Atrophy 
Ageing research reviews  2010;9(4):369-383.
Sarcopenia, the age-related loss of skeletal muscle mass, is a significant public health concern that continues to grow in relevance as the population ages. Certain conditions have the strong potential to coincide with sarcopenia to accelerate the progression of muscle atrophy in older adults. Among these conditions are co-morbid diseases common to older individuals such as cancer, kidney disease, diabetes, and peripheral artery disease. Furthermore, behaviors such as poor nutrition and physical inactivity are well-known to contribute to sarcopenia development. However, we argue that these behaviors are not inherent to the development of sarcopenia but rather accelerate its progression. In the present review, we discuss how these factors affect systemic and cellular mechanisms that contribute to skeletal muscle atrophy. In addition, we describe gaps in the literature concerning the role of these factors in accelerating sarcopenia progression. Elucidating biochemical pathways related to accelerated muscle atrophy may allow for improved discovery of therapeutic treatments related to sarcopenia.
PMCID: PMC3788572  PMID: 20438881
Aging; Proteolysis; Satellite Cells; HIV; COPD; Disability
12.  Investigations of botanicals on food intake, satiety, weight loss, and oxidative stress: a study protocol of a double-blind, placebo-controlled, crossover study 
Botanicals represent an important and underexplored source of potential new therapies that may facilitate caloric restriction and thereby produce long-term weight loss. In particular, one promising botanical that may reduce food intake and body weight by affecting neuroendocrine pathways related to satiety is Garcinia cambogia (Garcinia cambogia Desr.)-derived (−)-hydroxycitric acid (HCA).
Methods and Design
The objective of this article is to describe the protocol of a clinical trial designed to directly test the effect that Garcinia cambogia-derived HCA has on food intake, satiety, weight loss, and oxidative stress levels, and to serve as a model for similar trials. A total of 48 healthy, overweight and obese individuals (body mass index; BMI range = 25.0 – 39.9) between the ages of 50 to 70 will participate in this double-blind, placebo-controlled, crossover study designed to examine the effects of two doses of Garcinia cambogia-derived HCA on food intake, satiety, weight loss, and oxidative stress levels. This trial will take place at the University of Florida (UF)’s Aging and Rehabilitation Research Center (ARRC) and UF Clinical Research Center (CRC). Food intake represents the primary outcome measure and is calculated based on the total calories consumed at breakfast, lunch, and dinner meals during each test meal day at the CRC. This study can be completed with far fewer subjects than a parallel design.
Of the numerous botanical compounds, the compound Garcinia cambogia-derived HCA was selected for testing in the present study because of its potential to safely reduce food intake, body weight, and oxidative stress levels. We will review potential mechanisms of action and safety parameters throughout this clinical trial, which is registered at under NCT01238887.
Trial registration (Identifier: NCT01238887).
PMCID: PMC3772724  PMID: 22088584
Obesity; Botanicals; Weight Loss; Garcinia Cambogia; hydroxycitric acid; dietary supplement
13.  Use of a Computerized Tracking System to Monitor and Provide Feedback on Dietary Goals for Calorie-Restricted Diets: The POUNDS LOST Study 
The use of self-monitoring as a tool to facilitate behavioral modification is common in many lifestyle-based weight loss interventions. Electronic tracking programs, including computer-based systems and smart phone applications, have been developed to allow individuals to self-monitor their behavior digitally. These programs offer an advantage over traditional self-report modalities in that they can provide users with direct feedback about dietary and/or physical activity adherence levels and thereby assist them in real-time decision making. This article describes the use of an Internet-based computerized tracking system (CTS) that was developed specifically for the POUNDS LOST study, a 2-year randomized controlled trial designed to test the efficacy of four macronutrient diets for weight and fat reduction in healthy, overweight men and women (body mass index range = 25.0–39.9 kg/m2). The CTS served many functions in this study, including data collection, dietary and exercise assessment and feedback, messaging system, and report generation. Across all groups, participants with high usage of the CTS during the initial 8 weeks lost greater amounts of weight than participants with low usage (8.7% versus 5.5% of initial body weight, respectively; p < .001) at week 32. Rates of CTS utilization were highest during the first year of this 2-year intervention, and utilization of the CTS declined steadily over time. The unique features of the CTS combined with technological developments, such as smart phone applications, offer significant potential to improve the user’s self-monitoring experience and adherence to health promotion programs designed specifically for individuals with obesity and type 2 diabetes.
PMCID: PMC3570857  PMID: 23063049
computerized tracking system; self-monitoring; smart phones; weight loss
14.  Effects of Chromium Picolinate on Food Intake and Satiety 
Chromium picolinate (CrPic) has been shown to attenuate weight gain, but the mechanism underlying this effect is unknown.
We assessed the effect of CrPic in modulating food intake in healthy, overweight, adult women who reported craving carbohydrates (Study 1) and performed confirmatory studies in Sprague-Dawley rats (Study 2). Study 1 utilized a double-blind placebo-controlled design and randomly assigned 42 overweight adult women with carbohydrate cravings to receive 1,000 μg of chromium as CrPic or placebo for 8 weeks. Food intake at breakfast, lunch, and dinner was directly measured at baseline, week 1, and week 8. For Study 2, Sprague-Dawley rats were fasted for 24 h and subsequently injected intraperitoneally with 0, 1, 10, or 50 μg/kg CrPic. Subsequently, rats were implanted with an indwelling third ventricular cannula. Following recovery, 0, 0.4, 4, or 40 ng of CrPic was injected directly into the brain via the intracerebroventricular cannula, and spontaneous 24-h food intake was measured.
Study 1 demonstrated that CrPic, as compared to placebo, reduced food intake (P < 0.0001), hunger levels (P < 0.05), and fat cravings (P < 0.0001) and tended to decrease body weight (P = 0.08). In study 2, intraperitoneal administration resulted in a subtle decrease in food intake at only the highest dose (P = 0.03). However, when administered centrally, CrPic dose-dependently decreased food intake (P < 0.05).
These data suggest CrPic has a role in food intake regulation, which may be mediated by a direct effect on the brain.
PMCID: PMC2753428  PMID: 18715218
15.  Effects of Chromium Picolinate on Food Intake and Satiety 
Chromium picolinate (CrPic) has been shown to attenuate weight gain, but the mechanism underlying this effect is unknown.
We assessed the effect of CrPic in modulating food intake in healthy, overweight, adult women who reported craving carbohydrates (Study 1) and performed confirmatory studies in Sprague-Dawley rats (Study 2). Study 1 utilized a double-blind placebo-controlled design and randomly assigned 42 overweight adult women with carbohydrate cravings to receive 1,000 mg of CrPic or placebo for 8 weeks. Food intake at breakfast, lunch, and dinner was directly measured at baseline, week 1, and week 8. For Study 2, Sprague-Dawley rats were fasted for 24 h and subsequently injected intraperitoneally with 0, 1, 10, or 50 μg/kg CrPic. Subsequently, rats were implanted with an indwelling third ventricular cannula. Following recovery, 0, 0.4, 4, or 40 ng of CrPic was injected directly into the brain via the intracerebroventricular cannula, and spontaneous 24-h food intake was measured.
Study 1 demonstrated that CrPic, as compared to placebo, reduced food intake (P < 0.0001), hunger levels (P < 0.05), and fat cravings (P < 0.0001) and tended to decrease body weight (P = 0.08). In study 2, intraperitoneal administration resulted in a subtle decrease in food intake at only the highest dose (P = 0.03). However, when administered centrally, CrPic dose-dependently decreased food intake (P < 0.05).
These data suggest CrPic has a role in food intake regulation, which may be mediated by a direct effect on the brain.
PMCID: PMC2753428  PMID: 18715218
16.  Angiotensin-Converting Enzyme Inhibitor Use by Older Adults Is Associated with Greater Functional Responses to Exercise 
To assess the association between angiotensin converting enzyme inhibitors (ACEis) and improvements in the physical function of older adults in response to chronic exercise training.
Secondary analysis of the Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) study, a multisite randomized clinical trial to evaluate the effects of chronic exercise on the physical function of older adults at risk for mobility disability.
Four academic research centers within the United States.
Four hundred twenty-four individuals aged 70 to 89 with mild to moderate functional impairments categorized for this analysis as ACEi users, users of other antihypertensive drugs, or antihypertensive nonusers.
A 12-month intervention of structured physical activity (PA) or health education promoting successful aging (SA).
Change in walking speed during a 400-m test and performance on a battery of short-duration mobility tasks (Short Physical Performance Battery (SPPB)).
Physical activity significantly improved the adjusted walking speed of ACEi users (P < .001) but did not of nonusers. PA improved the adjusted SPPB score of ACEi users (P < .001) and of persons who used other antihypertensive drugs (P = .005) but not of antihypertensive nonusers (P = .91). The percentage of ACEi users deriving clinically significant benefit from exercise training for walking speed (30%) and SPPB score (48%) was dramatically higher than for nonusers (14% and 12%, respectively).
For older adults at risk for disability, exercise-derived improvements in physical function were greater for ACEi users than users of other antihypertensive drugs and antihypertensive nonusers.
PMCID: PMC3625953  PMID: 22726232
aging; exercise; physical function; LIFE Study; ACE inhibitors
17.  Effect of Diet Composition on Energy Expenditure during Weight Loss: The POUNDS LOST Study 
Weight loss reduces energy expenditure, but the contribution of different macronutrients to this change is unclear.
We tested the hypothesis that macronutrient composition of the diet might affect the partitioning of energy expenditure during weight loss.
A sub-study of 99 participants from the POUNDS LOST trial had total energy expenditure (TEE) measured by doubly labeled water and resting energy expenditure (REE) measured by indirect calorimetry at baseline and repeated at 6 months in 89 participants. Participants were randomly assigned to one of 4 diets with either 15% or 25% protein and 20% or 40% fat.
TEE and REE were positively correlated with each other and with fat free mass and body fat, at baseline and 6 months. The average weight loss of 8.1±0.65 kg (LSmean±SE) reduced TEE by 120±56 kcal/d and REE by 136±18 kcal/d. A greater weight loss at 6 months was associated with a greater decrease in TEE and REE. Participants eating the high fat diet lost significantly more fat free mass (1.52±0.55 kg) than the low fat diet group (p<0.05). Participants eating the low fat diet had significantly higher measures of physical activity than the high fat group.
A greater weight loss was associated with a larger decrease in both TEE and REE. The low fat diet was associated with significant changes in fat free body mass and energy expenditure from physical activity compared to the high fat diet.
PMCID: PMC3289771  PMID: 21946707
18.  Control in the Middle (CIM) for Three Period Crossover Studies 
Planta Medica  2011;77(13):1473-1476.
Three period crossover studies can be efficient and convenient methods of conducting Phase II clinical trials. Non-randomly placing control in the middle (CIM) has not been practiced, but may be extremely useful in studies testing herbal products for which placebos are not available, or for distinguishing between behavioral and biological effects. Furthermore, this design can serve as a valuable addition to classical studies of either (a) two competing treatments or (b) treatment versus placebo versus an open label “nothing” as the control. Therefore, we propose rigorous designs that will help practitioners efficiently answer research questions where (1) two active treatments need to be compared against each other with treatment vs. placebo comparisons of secondary importance; (2) a single active treatment needs to be tested where no placebo is available; or (3) the placebo effect is of interest in a treatment vs. placebo trial. For studies where no placebo is available, deception will be required, with participants told that in one randomly selected period (#1 or #3) they will receive the active treatment, and that they will receive a new experimental inert placebo in the other period. Assuming this design is approved by an ethics committee, it can be very useful in biomedical research.
PMCID: PMC3296130  PMID: 21509714
blinding; crossover study; deception; phase II clinical trial; placebo; washout
19.  An Exploratory Analysis of the Effects of a Weight Loss Plus Exercise Program on Cellular Quality Control Mechanisms in Older Overweight Women 
Rejuvenation Research  2011;14(3):315-324.
Obese older adults are particularly susceptible to sarcopenia and have a higher prevalence of disability than their peers of normal weight. Interventions to improve body composition in late life are crucial to maintaining independence. The main mechanisms underlying sarcopenia have not been determined conclusively, but chronic inflammation, apoptosis, and impaired mitochondrial function are believed to play important roles. It has yet to be determined whether impaired cellular quality control mechanisms contribute to this process. The objective of this study was to assess the effects of a 6-month weight loss program combined with moderate-intensity exercise on the cellular quality control mechanisms autophagy and ubiquitin-proteasome, as well as on inflammation, apoptosis, and mitochondrial function, in the skeletal muscle of older obese women. The intervention resulted in significant weight loss (8.0 ± 3.9 % vs. 0.4 ± 3.1% of baseline weight, p = 0.002) and improvements in walking speed (reduced time to walk 400 meters, − 20.4 ± 16% vs. − 2.5 ± 12%, p = 0.03). In the intervention group, we observed a three-fold increase in messenger RNA (mRNA) levels of the autophagy regulators LC3B, Atg7, and lysosome-associated membrane protein-2 (LAMP-2) compared to controls. Changes in mRNA levels of FoxO3A and its targets MuRF1, MAFBx, and BNIP3 were on average seven-fold higher in the intervention group compared to controls, but these differences were not statistically significant. Tumor necrosis factor-α (TNF-α) mRNA levels were elevated after the intervention, but we did not detect significant changes in the downstream apoptosis markers caspase 8 and 3. Mitochondrial biogenesis markers (PGC1α and TFAm) were increased by the intervention, but this was not accompanied by significant changes in mitochondrial complex content and activity. In conclusion, although exploratory in nature, this study is among the first to report the stimulation of cellular quality control mechanisms elicited by a weight loss and exercise program in older obese women.
PMCID: PMC3136739  PMID: 21631380
20.  Adherence is a multi-dimensional construct in the POUNDS LOST trial 
Journal of behavioral medicine  2009;33(1):35-46.
Research on the conceptualization of adherence to treatment has not addressed a key question: Is adherence best defined as being a uni-dimensional or multi-dimensional behavioral construct? The primary aim of this study was to test which of these conceptual models best described adherence to a weight management program. This ancillary study was conducted as a part of the POUNDS LOST trial that tested the efficacy of four dietary macro-nutrient compositions for promoting weight loss. A sample of 811 overweight/obese adults was recruited across two clinical sites, and each participant was randomly assigned to one of four macronutrient prescriptions: (1) Low fat (20% of energy), average protein (15% of energy); (2) High fat (40%), average protein (15%); (3) Low fat (20%), high protein (25%); (4) High fat (40%), high protein (25%). Throughout the first 6 months of the study, a computer tracking system collected data on eight indicators of adherence. Computer tracking data from the initial 6 months of the intervention were analyzed using exploratory and confirmatory analyses. Two factors (accounting for 66% of the variance) were identified and confirmed: (1) behavioral adherence and (2) dietary adherence. Behavioral adherence did not differ across the four interventions, but prescription of a high fat diet (vs. a low fat diet) was found to be associated with higher levels of dietary adherence. The findings of this study indicated that adherence to a weight management program was best conceptualized as being multi-dimensional, with two dimensions: behavioral and dietary adherence.
PMCID: PMC3153914  PMID: 19856202
Adherence; Overweight; Obesity; Randomized controlled trial; Lifestyle behavior modification
21.  Early behavioral adherence predicts short and long-term weight loss in the POUNDS LOST study 
Journal of behavioral medicine  2010;33(4):305-314.
The primary aim of this study was to test the association of early (first 6 months) adherence related to diet, self-monitoring, and attendance with changes in adiposity and cardiovascular risk factors. This study used data from the 24-month POUNDS LOST trial that tested the efficacy of four dietary macronutrient compositions for short-and long-term weight loss. A computer tracking system was used to record data on eight indicator variables related to adherence. Using canonical correlations at the 6 and 24 month measurement periods, early behavioral adherence was associated with changes in percent weight loss and waist circumference at 6 months (R = 0.52) and 24 months (R = 0.37), but was not associated with cardiovascular disease risk factor levels. Early dietary adherence was associated with changes in insulin at 6 months (R = 0.19), but not at 24 months (R = 0.08, ns). Early dietary adherence was not associated with changes in adiposity.
PMCID: PMC3150109  PMID: 20195742
Obesity; Weight management; Adherence; Computer tracking; Waist circumference; Insulin
22.  An Environmental Intervention to Prevent Excess Weight Gain in African American Students: A Pilot Study 
Examine the influence of an environmental intervention to prevent excess weight gain in African American children.
Single-group repeated measures.
The intervention was delivered to a school composed of African American children.
Approximately 45% (N = 77) of enrolled second through sixth grade students.
The 18-month intervention was designed to alter the school environment to prevent excess weight gain by making healthier eating choices and physical activity opportunities more available.
Body Mass Index Percentile was the primary outcome variable. Body mass index Z-score was also calculated, and percent body fat, using bioelectrical impedance, was also measured. Total caloric intake (kcal), and percent kcal from fat, carbohydrate, and protein were measured by digital photography. Minutes of physical activity and sedentary behavior were self-reported.
Mixed models analysis was used, covarying baseline values.
Boys maintained while girls increased percent body fat over 18-months (p = .027). All children decreased percent of kcal consumed from total and saturated fat, and increased carbohydrate intake and self-reported physical activity during the intervention (p values < .025). body mass index Z-score, sedentary behavior, and total caloric intake were unchanged.
The program may have resulted in maintenance of percent body fat in boys. Girl's percent body fat steadily increased, despite similar behavioral changes as boys. School-based interventions targeting African American children should investigate strategies that can be effective across gender.
PMCID: PMC2871317  PMID: 20465148
blacks; obesity; children; nutrition; physical activity; Manuscript format: research; Research purpose: intervention testing/program evaluation; Study design: quasi-experimental; Outcome measure: behavioral; Setting: school; Health focus: weight control; Strategy: environmental change; Target population age: youth; Target population circumstances: race/ethnicity
23.  Cellular mechanisms of cardioprotection by calorie restriction: state of the science and future perspectives 
Clinics in geriatric medicine  2009;25(4):715-732.
Evidence from animal models and preliminary studies in humans indicate that calorie restriction (CR) delays cardiac aging and can prevent cardiovascular disease. These effects are mediated by a wide spectrum of biochemical and cellular adaptations, including redox homeostasis, mitochondrial function, inflammation, apoptosis and autophagy. Despite the beneficial effects of CR, its large-scale implementation is challenged by applicability issues as well as health concerns. However, preclinical studies indicate that specific compounds, such as resveratrol, may mimic many of the effects of CR, thus potentially obviating the need for drastic food intake reductions. Results from ongoing clinical trials will reveal whether the intriguing alternative of CR mimetics represents a safe and effective strategy to promote cardiovascular health and delay cardiac aging in humans.
PMCID: PMC2786899  PMID: 19944269
Cardiovascular disease; oxidative stress; inflammation; apoptosis; autophagy; calorie restriction mimetics
24.  Beneficial Effects of a Q-ter® Based Nutritional Mixture on Functional Performance, Mitochondrial Function, and Oxidative Stress in Rats 
PLoS ONE  2010;5(5):e10572.
Mitochondrial dysfunction and oxidative stress are central mechanisms underlying the aging process and the pathogenesis of many age-related diseases. Selected antioxidants and specific combinations of nutritional compounds could target many biochemical pathways that affect both oxidative stress and mitochondrial function and, thereby, preserve or enhance physical performance.
Methodology/Principal Findings
In this study, we evaluated the potential anti-aging benefits of a Q-ter® based nutritional mixture (commercially known as Eufortyn®) mainly containing the following compounds: terclatrated coenzyme Q10 (Q-ter®), creatine and a standardized ginseng extract. We found that Eufortyn® supplementation significantly ameliorated the age-associated decreases in grip strength and gastrocnemius subsarcolemmal mitochondria Ca2+ retention capacity when initiated in male Fischer344 x Brown Norway rats at 21 months, but not 29 months, of age. Moreover, the increases in muscle RNA oxidation and subsarcolemmal mitochondrial protein carbonyl levels, as well as the decline of total urine antioxidant power, which develop late in life, were mitigated by Eufortyn® supplementation in rats at 29 months of age.
These data imply that Eufortyn® is efficacious in reducing oxidative damage, improving the age-related mitochondrial functional decline, and preserving physical performance when initiated in animals at early midlife (21 months). The efficacy varied, however, according to the age at which the supplementation was provided, as initiation in late middle age (29 months) was incapable of restoring grip strength and mitochondrial function. Therefore, the Eufortyn® supplementation may be particularly beneficial when initiated prior to major biological and functional declines that appear to occur with advancing age.
PMCID: PMC2868025  PMID: 20485503
25.  The association between energy intake and viewing television, distractibility, and memory for advertisements 
The effect of television viewing (TVV) with and without advertisements (ads) on energy intake is unclear.
To test: 1) the effect of TVV, with and without ads, on energy intake compared to a control and reading condition, and 2) the association of distractibility and memory for ads with energy intake and body weight.
Forty-eight (26 female) adults (age 19 to 54 years) with body mass index 20 to 35 kg/m2 completed this laboratory-based study. All participants completed four buffet-style meals in random order: 1) control, 2) reading, 3) TV-with food and non-food ads (TV-ads), 4) TV-no ads. Energy intake was quantified by weighing foods. Distractibility and memory for ads in the TV-ads condition were quantified with a norm-referenced test and recognition task, respectively.
Repeated measures analysis of variance indicated that energy and macronutrient intake did not differ significantly among the four conditions (p-values>0.65). Controlling for sex, memory for advertisements was associated with body weight (r=0.36, p<0.05) and energy intake, but only when viewing TV (r=0.39, p<0.05 during the TV-no ads condition and r=0.29, p=0.06 during the TV-ads condition). Controlling for sex, distractibility was associated with body weight (r=0.36, p<0.05), but not energy intake. Distractibility, however, accounted for 13% of the variance in men's energy intake (p=0.11).
TVV did not affect energy intake, but individual characteristics (memory for advertisements) were associated with body weight and energy intake in certain conditions. These characteristics should be considered in food intake and intervention studies.
PMCID: PMC2615456  PMID: 19056603
food intake; television; advertisements; energy intake; television viewing

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