Animal studies have shown that life span is extended by caloric restriction (CR). This manuscript describes the design and methodology of an innovative CR intervention, which is the treatment arm of the CALERIE study. This study is a multi-center, randomized controlled trial examining the effects of two years of CR on biomarkers of longevity among non-obese (BMI ≥ 22 kg/m2 and < 28 kg/m2) adults. CALERIE is the first investigation of the effects of long-term CR on the aging process in non-obese humans. 220 healthy volunteers across 3 sites were recruited beginning in May 2007. Participants were randomized in a 2:1 ratio between the CR or Control group (i.e., ad libitum diet). An intensive intervention was designed to assist participants in adhering to the 25% CR prescription for a two-year duration. The intervention was designed to optimize the likelihood 25% CR would be achieved through a variety of nutritional and behavioral strategies, several of which are innovative methods for achieving CR. The intervention includes the following components: an intensive, “mixed” format schedule of group/individual sessions, meal provision phase with exposure to various diets, Personal Digital Assistants to monitor caloric intake, unique portion estimation training, tailored treatment using a computer tracking system, toolbox strategies and algorithms, as well as comprehensive coverage of nutrition and behavioral topics in order to assist participants in meeting their CR goal. This manuscript provides an overview of the CR intensive intervention and may be of assistance for other researchers and clinicians in designing future trials.

Background

The primary aims of this article are to describe the utilization of an Internet-based weight management Web site [Healthy Eating, Activity, and Lifestyle Training Headquarters (H.E.A.L.T.H.)] over a 12–27 month period and to describe concurrent weight and fitness changes in Army Reserve soldiers.

Methods

The H.E.A.L.T.H. Web site was marketed to Army Reserve soldiers via a Web site promotion program for 27 months (phase I) and its continued usage was observed over a subsequent 12-month period (phase II). Web site usage was obtained from the H.E.A.L.T.H. Web site. Weight and fitness data were extracted from the Regional Level Application Software (RLAS).

Results

A total of 1499 Army Reserve soldiers registered on the H.E.A.L.T.H. Web site. There were 118 soldiers who returned to the H.E.A.L.T.H. Web site more than once. Registration rate reduced significantly following the removal of the Web site promotion program. During phase I, 778 Army Reserve soldiers had longitudinal weight and fitness data in RLAS. Men exceeding the screening table weight gained less weight compared with men below it (p < .007). Percentage change in body weight was inversely associated with change in fitness scores.

Conclusions

The Web site promotion program resulted in 52% of available Army Reserve soldiers registering onto the H.E.A.L.T.H. Web site, and 7.9% used the Web site more than once. The H.E.A.L.T.H. Web site may be a viable population-based weight and fitness management tool for soldier use.

Background

Weight loss reduces energy expenditure, but the contribution of different macronutrients to this change is unclear.

Hypothesis

We tested the hypothesis that macronutrient composition of the diet might affect the partitioning of energy expenditure during weight loss.

Design

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.

Results

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.

Conclusion

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.

Background

Objective measures are needed to quantify dietary adherence during caloric restriction (CR) while participants are free-living. One method to monitor adherence is to compare observed weight loss to the expected weight loss during a prescribed level of CR. Normograms (graphs) of expected weight loss can be created from mathematical modeling of weight change to a given level of CR, conditional on the individual's set of baseline characteristics. These normograms can then be used by counselors to help the participant adhere to their caloric target.

Purpose

(1) To develop models of weight loss over a year of caloric restriction given demographics (age and sex), and well defined measurements of of Body Mass Index, total daily energy expenditure (TDEE) and %CR. (2) To utilize these models to develop normograms given level of caloric restriction, and measures of these variables.

Methods

Seventy-seven individuals completing a 6-12 month CR intervention (CALERIE) had body weight and body composition measured frequently. Energy intake (and %CR) was estimated from TDEE (by doubly labeled water) and body composition (by DXA) at baseline and months 1, 3, 6 and 12. Body weight was modeled to determine the predictors and distribution of the expected trajectory of percent weight change over 12 months of caloric restriction.

Results

As expected, CR was related to change in body weight. Controlling for time-varying measures, initially simple models of the functional form indicated that the trajectory of percent weight change was predicted by a non-linear function of initial age, TDEE, %CR, and sex. Using these estimates, normograms for the weight change expected during a 25%CR were developed. Our model estimates that the mean weight loss (% change from baseline weight) for an individual adherent to a 25% CR regimen is -10.9±6.3% for females and -13.9±6.4% for men after 12 months.

Limitations

There are several limitations. Sample sizes are small (n=77), and, by design, the protocols, including prescribed CR, for the interventions differed by site, and not all subjects completed a year of follow-up. In addition, the inclusion of subjects by age and initial BMI was constricted so that these results may no generalize to other older, obese subjects.

Conclusions

The trajectory of percent weight change during CR interventions in the presence of well measured covariates can be modeled using simple non-linear functions, and is related level of CR, the percent change in TDEE, gender, and age. Displayed on a normogram, individually tailored trajectories can be used by counselors and participants to monitor weight loss and adherence to a CR regimen.

Background

A significant number of soldiers exceed the maximum allowable weight standards or have body weights approaching the maximum allowable weight standards. This mandates development of scalable approaches to improve compliance with military weight standards.

Methods

We developed an intervention that included two components: (1) an Internet-based weight management program (Web site) and (2) a promotion program designed to promote and sustain usage of the Web site. The Web site remained online for 37 months, with the Web site promotion program ending after 25 months.

Results

Soldiers’ demographics were as follows: mean age, 32 years; body mass index (BMI), 28 kg/m2; 31% female; and 58% Caucasian. Civilian demographics were as follows: mean age, 38 years; BMI, 30 kg/m2; 84% female; and 55% Caucasian. Results indicated that 2417 soldiers and 2147 civilians (N = 4564) registered on the Web site. In the first 25 months (phase 1) of the study, new participants enrolled on the Web site at a rate of 88 (soldiers) and 80 (civilians) per month. After the promotion program was removed (phase 2), new participants enrolled at a rate of 18 (soldiers) and 13 (civilians) per month. Utilization of the Web site was associated with self-reported weight loss (p < .0001). Participants who utilized the Web site more frequently lost more weight (p < .0001). Participants reported satisfaction with the Web site.

Conclusions

The Web site and accompanying promotion program, when implemented at a military base, received satisfactory ratings and benefited a subset of participants in promoting weight loss. This justifies further examination of effectiveness in a randomized trial setting.

The obesity epidemic had spawned considerable interest in understanding peoples' responses to palatable food cues that are plentiful in obesogenic environments. In this paper we examine how trait mindfulness of older, obese adults may moderate brain networks that arise from exposure to such cues. Nineteen older, obese adults came to our laboratory on two different occasions. Both times they ate a controlled breakfast meal and then were restricted from eating for 2.5 h. After this brief period of food restriction, they had an fMRI scan in which they were exposed to food cues and then underwent a 5 min recovery period to evaluate brain networks at rest. On one day they consumed a BOOST® liquid meal prior to scanning, whereas on the other day they only consumed water (NO BOOST® condition). We found that adults high in trait mindfulness were able to return to their default mode network (DMN), as indicated by greater global efficiency in the precuneus, during the post-exposure rest period. This effect was stronger for the BOOST® than NO BOOST® treatment condition. Older adults low in trait mindfulness did not exhibit this pattern in the DMN. In fact, the brain networks of those low on the MAAS suggests that they continued to be pre-occupied with the elaboration of food cues even after cue exposure had ended. Further work is needed to examine whether mindfulness-based therapies alter brain networks to food cues and whether these changes are related to eating behavior.

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.

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.

Purpose

Examine the influence of an environmental intervention to prevent excess weight gain in African American children.

Design

Single-group repeated measures.

Setting

The intervention was delivered to a school composed of African American children.

Subjects

Approximately 45% (N = 77) of enrolled second through sixth grade students.

Intervention

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.

Measures

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.

Analysis

Mixed models analysis was used, covarying baseline values.

Results

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.

Conclusion

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.

Background

Childhood obesity is a growing problem, particularly in rural, Louisiana school children. Traditionally, school-based obesity prevention programs have used a primary prevention approach. Finding methods to deliver secondary prevention programs to large numbers of students without singling out overweight students has been a challenge. An innovative approach to achieving this goal is through use of an Internet intervention targeted toward a student's weight status. This article describes the Louisiana (LA) Health Internet intervention, including the student Web site, the Internet counselor Web site, and the Internet counseling process.

Method

The LA Health Internet intervention had separate interfaces for students and Internet counselors. The main features of the student site were behavioral weight loss lessons, lesson activities, chat with an Internet counselor, and email. The Internet counselor site contained these same features, plus a student directory and various means of obtaining student information to guide counseling. Based on their baseline weight status, students received lessons and counseling that promoted either weight loss or weight maintenance. Intervention was delivered during class time, and teachers scheduled Internet counseling sessions with intervention personnel.

Results

The LA Health Internet intervention was initially implemented within 14 schools; 773 students were granted access to the site. From Fall 2007 to Spring 2009, 1174 hours of Internet counselor coverage was needed to implement the Internet counseling component of this intervention

Conclusion

The LA Health Internet intervention is an innovative and feasible method of delivering a secondary prevention program within a school setting to large numbers of students.

Summary

Lifespan in rodents is prolonged by caloric restriction (CR) and by mutations affecting the somatotropic axis. It is not known if CR can alter the age-associated decline in GH, IGF-1 and GH secretion.

Aim

To evaluate the effect of caloric restriction on GH secretory dynamics.

Methods

Forty-three young (36.8±1.0y), overweight (BMI 27.8±0.7) men (n=20) and women (n=23) were randomized into four groups; Control=100% of energy requirements; CR=25% calorie restriction; CR+EX=12.5% CR+12.5% increase in energy expenditure by structured exercise; LCD=low calorie diet until 15% weight reduction followed by weight maintenance. At baseline and after six months, body composition (DXA), abdominal visceral fat (CT) 11-h GH secretion (blood sampling every 10 min for 11 hours; 2100h-0800h) and deconvolution analysis were measured.

Results

After six months, weight (Control:−1±1%, CR:−10±1%, CR+EX:−10±1%, LCD:−14±1%), fat mass (Control:−2±3%, CR:−24±3%, CR+EX:−25±3%, LCD:−31±2%), and visceral fat (Control: −2±4%, CR:−28±4%, CR+EX:−27±3%, LCD:−36±2%) were significantly (p<.001) reduced in the three intervention groups compared to control. Mean 11-h GH concentrations were not changed in CR or control but increased in CR+EX (p<.0001) and LCD (p<.0001) because of increased secretory burst mass (CR+EX: 34±13%, LCD: 27±22%, p<0.05) and amplitude (CR+EX: 34±14%, LCD: 30±20%, p<0.05) but not to changes in secretory burst frequency or GH half-life. Fasting ghrelin was significantly increased from baseline in all three intervention groups however total IGF-1 concentrations were increased only in CR+EX (10±7%, p<0.05) and LCD (19±4%, p<0.001).

Conclusion

A 25% CR diet for 6 months does not change GH, GH secretion or IGF-1 in non-obese men and women.

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.

Calorie restriction (CR) delays the development of age-associated disease and increases lifespan in rodents, but the effects in humans remain uncertain.

Purpose

Determine the effect of 6 months of CR with or without exercise on cardiovascular disease (CVD) risk factors and estimated 10-year CVD risk in healthy non-obese men and women.

Methods

Thirty-six individuals were randomized to one of three groups for 6 months: Control, 100% of energy requirements; CR, 25% calorie restriction; CR+EX, 12.5% CR + 12.5% increase in energy expenditure via aerobic exercise. CVD risk factors were assessed at baseline, 3 and 6 months.

Results

After 6 months, CR and CR+EX lost approximately 10% of body weight. CR significantly reduced triacylglycerol (-31 ± 15 mg/dL) and factor VIIc (-10.7 ± 2.3%). Similarly CR+EX reduced triacylglycerol (-22 ± 8 mg/dL) and additionally reduced LDL-C (-16.0 ± 5.1 mg/dL) and DBP (-4.0 ± 2.1 mmHg). In contrast, both triacylglycerol (24 ± 14 mg/dL) and factor VIIc (7.9 ± 2.3%) were increased in the control group. HDL-cholesterol was increased in all groups while hsCRP was lower in the Controls vs. CR+EX. Estimated 10-year CVD risk significantly declined from baseline by 29% in CR (P< 0.001) and 38% in the CR+EX (P<0.001) while remaining unchanged in the Control group.

Conclusions

Based on combined favorable changes in lipid and blood pressure, caloric restriction with or without exercise that induces weight loss favorably reduces risk for CVD even in already healthy non-obese individuals.

Context

Inconsistent findings have been reported regarding improved health-related quality of life (HRQOL) following weight loss.

Objective

To test the efficacy of a weight management program for improving HRQOL in overweight/obese adults diagnosed with type 2 diabetes.

Design

Randomized multi-site clinical trial with two treatment arms and blinded measurements at baseline and end of Year 1.

Setting

Study was conducted at 16 outpatient research centers.

Participants

Total of 5,145 participants (mean age = 58.7±6.9 yr; mean BMI = 36.0±5.9; % women = 59.5%; % white = 63.3%) were randomized to two treatment arms.

Intervention

The two treatment arms were: Intensive Lifestyle Intervention 1 and Diabetes Support and Education (DSE).

Main Outcome Measures

SF-36, physical (PCS) and mental health (MCS) summary scores, and Beck Depression Inventory-II (BDI-II) scores. Baseline means were: PCS = 47.9±7.9; MCS = 54.0±8.1; and BDI-II = 5.7±5.0.

Results

HRQOL, as measured by PCS and BDI-II scores, improved (p<0.001) in the ILI arm compared to the DSE arm. The largest effect was observed for PCS (difference = −2.91, 99% CI: −3.44 ~ −2.37). HRQOL improved greatest in participants with the lowest baseline levels of quality of life. Changes in weight (ILI = −8.77±8.2 kg; DSE = −0.86±5.0 kg), improved fitness, and improved physical complaints mediated treatment effects associated with BDI-II and PCS.

Conclusions

HRQOL was significantly improved in overweight adults diagnosed with type 2 diabetes by enrollment in a weight management program that yielded significant weight loss, improved physical fitness, and reduced physical complaints. Trial Registration: NCT00017953

Objective

Rates of obesity among children have been rising in recent years. Information on the prevalence of obesity in children living in rural communities is needed. We report the prevalence of overweight and obesity in children enrolled in grades 4 to 6 who live in rural areas of Louisiana, U.S.

Methods and Procedures

These data were collected as baseline assessment for the Louisiana (LA) Health project. Height, weight, and estimates of body fat (using body impedance analysis) were collected on 2709 children. Average age was 10.5 years and the sample composition was 57.3% girls, 61.7% African-American, 36.0% Caucasian, and 2.3% other minority. A majority of children (77%) met the criterion for poverty status.

Results

The distribution of body mass index (BMI) percentile was highly skewed toward obesity. The most frequent BMI percentile scores were 98th and 99th percentile. Using Centers for Disease Control and Prevention (CDC) norms, the overall prevalence of obesity was 27.4% and for overweight was 45.1% of which 17.7% were between the 85th and 95th percentile. The prevalence of childhood overweight and obesity were much higher than the national norm and this increased prevalence was observed in both genders and in Caucasian and African American children.

Discussion

The prevalence of childhood overweight and obesity was found to be much higher in rural and primarily poor (77%) children living in Louisiana when compared to national norms. This observation suggests that rural children from Louisiana may be experiencing an epidemic of obesity that exceeds national prevalence estimates.

Context

Binge eating (BE) is common in overweight and obese individuals with type 2 diabetes yet little is known about how BE affects weight loss in this population.

Objective

To determine whether BE was related to 1-year weight losses in overweight and obese individuals with type 2 diabetes participating in an ongoing clinical trial.

Design and Setting

Look AHEAD is a randomized controlled trial examining the long-term effect of intentional weight loss on CVD in overweight and obese adults with type 2 diabetes.

Participants

Overweight and obese individuals, 45–76 years old, with type 2 diabetes (n=5145).

Interventions

Participants were randomly assigned to an intensive lifestyle intervention (ILI) or to enhanced usual care (DSE).

Main outcome measures

At baseline and 1-year, participants had their weight measured and completed a fitness test and self-report measures of BE and dietary intake. Four groups were created based on BE status at baseline and 1-year (Yes/Yes, No/No, Yes/No, No/Yes). Analyses controlled for baseline differences between binge eaters and non-binge eaters.

Results

Most individuals (85.4%) did not report BE at baseline or 1-year, 7.5% reported BE only at baseline, 3.7% reported BE at both times, and 3.4% reported BE only at 1-year, with no differences between ILI and DSE conditions (p=.14). Across ILI and DSE, greater weight losses were observed in participants who stopped BE at 1-year (5.3±.4 kg) and in those who reported no BE at either time point (4.8±.1 kg) than in those who continued to BE (3.1±.6 kg) and those who began BE at 1-year (3.0±.6 kg) (p=.0003). Post hoc analyses suggested these differences were due to changes in caloric intake.

Conclusions

Overweight and obese individuals with type 2 diabetes who stop binge eating appear just as successful at weight loss as non-binge eaters after one year of treatment.

BACKGROUND

The possible advantage for weight loss of a diet that emphasizes protein, fat, or carbohydrates has not been established, and there are few studies that extend beyond 1 year.

METHODS

We randomly assigned 811 overweight adults to one of four diets; the targeted percentages of energy derived from fat, protein, and carbohydrates in the four diets were 20, 15, and 65%; 20, 25, and 55%; 40, 15, and 45%; and 40, 25, and 35%. The diets consisted of similar foods and met guidelines for cardiovascular health. The participants were offered group and individual instructional sessions for 2 years. The primary outcome was the change in body weight after 2 years in two-by-two factorial comparisons of low fat versus high fat and average protein versus high protein and in the comparison of highest and lowest carbohydrate content.

RESULTS

At 6 months, participants assigned to each diet had lost an average of 6 kg, which represented 7% of their initial weight; they began to regain weight after 12 months. By 2 years, weight loss remained similar in those who were assigned to a diet with 15% protein and those assigned to a diet with 25% protein (3.0 and 3.6 kg, respectively); in those assigned to a diet with 20% fat and those assigned to a diet with 40% fat (3.3 kg for both groups); and in those assigned to a diet with 65% carbohydrates and those assigned to a diet with 35% carbohydrates (2.9 and 3.4 kg, respectively) (P>0.20 for all comparisons). Among the 80% of participants who completed the trial, the average weight loss was 4 kg; 14 to 15% of the participants had a reduction of at least 10% of their initial body weight. Satiety, hunger, satisfaction with the diet, and attendance at group sessions were similar for all diets; attendance was strongly associated with weight loss (0.2 kg per session attended). The diets improved lipid-related risk factors and fasting insulin levels.

CONCLUSIONS

Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize.

The Department of Defense (DoD) has mandated development of a system to collect and manage data on the weight, percent body fat (%BF), and fitness of all military personnel. This project aimed to (1) develop a computerized weight and fitness database to track individuals and Army units over time allowing cross-sectional and longitudinal evaluations and (2) test the computerized system for feasibility and integrity of data collection over several years of usage. The computer application, the Military Services Fitness Database (MSFD), was designed for (1) storage and tracking of data related to height, weight, %BF for the Army Weight Control Program (AWCP) and Army Physical Fitness Test (APFT) scores and (2) generation of reports using these data. A 2.5-year pilot test of the MSFD indicated that it monitors population and individual trends of changing body weight, %BF, and fitness in a military population.

Abstract

Background

Chromium picolinate (CrPic) has been shown to attenuate weight gain, but the mechanism underlying this effect is unknown.

Methods

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.

Results

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).

Conclusions

These data suggest CrPic has a role in food intake regulation, which may be mediated by a direct effect on the brain.

Background:

Chromium picolinate (CrPic) has been shown to attenuate weight gain, but the mechanism underlying this effect is unknown.

Methods:

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.

Results:

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).

Conclusions:

These data suggest CrPic has a role in food intake regulation, which may be mediated by a direct effect on the brain.

objective

Nonalcoholic fatty liver disease (NAFLD) and its association with insulin resistance are increasingly recognized as major health burdens. The main objectives of this study were to assess the relation between liver lipid content and serum lipids, markers of liver function and inflammation in healthy overweight subjects, and to determine whether caloric restriction (CR) (which improves insulin resistance) reduces liver lipids in association with these same measures.

Methods and Procedures

Forty-six white and black overweight men and women (BMI = 24.7-31.3 kg/m2) were randomized to “control (CO)” = 100% energy requirements; “CR” = 25%; “caloric restriction and increased structured exercise (CR+EX)”= 12.5% CR + 12.5% increase in energy expenditure through exercise; or “low-calorie diet (LCD)” = 15% weight loss by liquid diet followed by weight-maintenance, for 6 months. Liver lipid content was assessed by magnetic resonance spectroscopy (MRS) and computed tomography (CT). Lipid concentrations, markers of liver function (alanine aminotransferase (ALT), alkaline phosphatase (ALK)), and whole-body inflammation (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP)) were measured in fasting blood.

Results

At baseline, increased liver lipid content (by MRS) correlated (P < 0.05) with elevated fasting triglyceride (r = 0.52), ALT (r = 0.42), and hsCRP (r = 0.33) concentrations after adjusting for sex, race, and alcohol consumption. With CR, liver lipid content was significantly lowered by CR, CR+EX, and LCD (detected by MRS only). The reduction in liver lipid content, however, was not significantly correlated with the reduction in triglycerides (r = 0.26; P = 0.11) or with the changes in ALT, high-density lipoprotein (HDL)-cholesterol, or markers of whole-body inflammation.

Discussion

CR may be beneficial for reducing liver lipid and lowering triglycerides in overweight subjects without known NAFLD.

This study tested the psychometric characteristics of the Body Morph Assessment version 2.0 (BMA 2.0). A sample of 563 adults composed of four groups classified by gender and ethnicity (Caucasian men and women and African-American men and women) were studied. Support for the internal consistency and test–retest reliability of the BMA 2.0 was found for both men and women. A study of convergent validity was conducted. The BMA 2.0 was found to have adequate reliability and validity. Norms were established for the BMA 2.0 estimates of current body size (CBS), ideal body size (IBS), and acceptable body size (ABS) for Caucasian and African-American men and women. In summary, the BMA 2.0 is a reliable and valid computerized measure of CBS, IBS, ABS, the CBS–IBS discrepancy (body dissatisfaction), and provides an estimate of over/underestimation of body size as compared to individuals of the same sex and body mass index.

There is a worldwide epidemic of obesity with far-reaching consequences for the health of our nation. Prevention of obesity, especially in children, has been deemed by public health policy makers to be one of the most important objectives for our country. This prevention project, called Louisiana (LA) Health, will test whether modification of environmental and behavioral factors can prevent inappropriate weight gain in children from rural parishes of Louisiana who are enrolled in the fourth to sixth grades during Year 1. The primary aim of the LA Health project is to test the efficacy of two school-based approaches for obesity prevention: primary prevention alone and a combination of primary and secondary prevention which will be compared to a no-intervention control group using a cluster randomization research design, with 17 school clusters randomly assigned to the three treatment arms. The study will span three years and will provide critical tests of strategies that: 1) modify the child’s environment as a primary prevention strategy and 2) provide health behavior modification via classroom instruction and internet counseling as a secondary prevention strategy. The study will also recruit a similar sample of students to measure changes in body weight relative to height, gender, and age over the same three-year period.

The focus of this review is on current research involving long-term calorie restriction (CR) and the resulting changes observed in physiological and behavioral outcomes in humans. Special emphasis will be given to the first completed clinical studies which are currently investigating the effects of controlled, high-quality energy-restricted diets on both biomarkers of longevity and on the development of chronic diseases related to age in humans. Prolonged CR has been shown to extend both the median and maximal lifespan in a variety of lower species such as yeast, worms, fish, rats, and mice. Mechanisms of this CR-mediated lifespan extension are not fully elucidated, but possibly involve significant alterations in energy metabolism, oxidative damage, insulin sensitivity, and functional changes in both the neuroendocrine and sympathetic nervous systems. In this brief report, we review some of the major physiological, psychological and behavioral changes after 6 month of CR in overweight otherwise healthy volunteers. Ongoing studies of prolonged CR in humans are now making it possible to analyze changes in “biomarkers of longevity” to unravel some of the mechanisms of its anti-aging phenomenon. With the incremental expansion of research endeavors in the area of energy or calorie restriction, data on the effects of CR in animal models and human subjects are becoming more accessible. Detailed analyses from controlled human trials involving long-term CR will allow investigators to link observed alterations from body composition down to changes in molecular pathways and gene expression, with their possible effects on the biomarkers of aging.

Context

Prolonged calorie restriction (CR) increases lifespan in rodents. Whether prolonged CR affects biomarkers of longevity, markers of oxidative stress, and reduces metabolic rate, beyond that expected from reduced metabolic mass, has not previously been tested in humans.

Objectives

To examine the effects of 6 months of calorie restriction, with or without exercise in nonobese (25≤BMI<30) humans.

Design, Setting, and Participants

Healthy, sedentary men and women (n=48) were randomized to one of four groups for 6-mo; Control=100% of energy requirements; CR=25% diet restriction; CREX=12.5%CR+12.5% increase in energy expenditure; LCD=low calorie diet until 15% weight reduction followed by weight maintenance.

Main Outcome Measures

Body composition, dehydroepiandrosterone sulfate (DHEAS), glucose, insulin, protein carbonyls, DNA damage, 24h energy expenditure (24h-EE, metabolic chamber) and core body temperature.

Results

Weight change at M6 was -1.0(1.1)% (Control), -10.4(0.9)% (CR), -10.0(0.8)% (CREX), -13.9(0.7)% (LCD). At M6, fasting insulin was reduced from baseline in CR, CREX and LCD groups (all, p<0.01), whereas DHEAS and glucose were unchanged. Core temperature was reduced in CR by 0.2(0.05)°C and by 0.3(0.08)°C in CREX (both, p<0.05). After adjustment for changes in body composition, sedentary 24h-EE was unchanged in controls (-18(52) kcal/d; p>0.05), but decreased in CR (-135(42)kcal/d), CREX (-117(52)kcal/d) and LCD (-125(35)kcal/d, (all, p<0.008). These “metabolic adaptations” (~6% more than expected based on loss of metabolic mass) were statistically different from controls (p<0.05). DNA damage was also reduced from baseline in CR, CREX and LCD groups at M6 (p≤ 0.002).

Conclusion

These results show that two previously reported biomarkers of longevity (fasting insulin and body temperature) are reduced by prolonged CR in humans and support the theory that metabolic rate is reduced beyond the level expected for reduced metabolic body size. Studies of longer duration are now required to determine if CR attenuates the aging process in humans.