The growing obesity epidemic is a world wide concern [1
]. Obesity contributes to health issues that result from carrying increased fat mass such as sleep apnea, osteoarthritis and joint and skin abnormalities and health issues that result from the metabolic effect of fat cells such as type 2 diabetes, insulin resistance, metabolic syndrome, hypertension, nonalcoholic fatty liver disease, heart disease, gallbladder disease and cancer [2
]. Decreasing body fat mass in humans significantly reduces health issues that arise from increased body fat [2
An effective approach to weight management is to increase dietary protein or change the ratio of carbohydrate to protein in the diet [4
]. A low carbohydrate to protein ratio (<2) with greater than 100 grams of protein per day in the form of meats, eggs, cheese, milk and nuts increased fat loss and retained lean muscle during dieting [5
]. Layman et al. [5
] studied body composition and weight loss in women who consumed a hypocaloric diet with a 1.4 or a 3.5 carbohydrate to protein ratio. Weight loss was not significantly different between groups but fat loss significantly increased for those consuming the high protein diet (~125 g/day). Skov et al. [8
] measured the effect of carbohydrate to protein ratio on body composition in a hypocaloric study. The treatment group consumed an ad libitum
fat-reduced diet with a 1.9 carbohydrate to protein ratio and the control group consumed an ad libitum
fat reduced diet with a 4.9 carbohydrate to protein ratio. The weight and fat losses over six months significantly increased in the high protein group compared to the control group (8.0 kg versus 5.1 kg for weight loss and 7.6 versus 4.3 kg for fat loss).
Increasing fat loss through dietary changes helps retain lean muscle mass. Retaining lean muscle translates into increased body strength, increased basal metabolic rate and increased bone strength [9
]. The retention of lean muscle during weight loss may be related to the leucine's ability to stimulate muscle synthesis [10
]. The post-prandial rate of protein synthesis also depends on the speed of protein absorption. Fast absorbing protein has an anabolic effect [11
]. The high leucine content (50–75% more than other common food proteins) of whey proteins [10
] coupled with fast absorption [11
] make whey protein ideal as a protein supplement during weight loss.
Whey proteins also modulate several hormones that influence body composition. Short term acute studies with whey proteins corroborate the body composition changes seen with longer term feeding studies. Whey protein isolate (75 grams per dose) was evaluated [12
] for its impact on obesity-related hormones in an acute (5 hour) protein ingestion in overweight and obese women with polycystic ovary syndrome (PCOS). The acute hormonal response showed significantly lower hyperinsulinemia (less lipogenesis), lower cortisol levels (lean muscle preservation) and increased ghrelin release (satiety enhancement).
Another dietary approach to decrease body fat is to increase dietary calcium. Increasing dietary calcium decreased body fat and improved body composition in several studies [13
]. Two different mechanisms have been suggested and include the formation of calcium soaps and decreased intestinal absorption of fat [21
] or an indirect hormonal mechanism [19
] that increases lipolysis in adipocyte tissue.
Several studies [23
] show that calcium supplementation with dairy products may arrest bone resorption during weight loss, provide stronger bones and reduce the potential for fractures after weight loss particularly in women over 65. Women over 65 who lose weight are at least 1.8 times more likely to have a bone fracture compared to counterparts that do not lose weight [25
]. Other benefits of dairy minerals include research showing that milk minerals decrease co-morbidities that are associated with obesity such as hypertension [26
] and stroke [27
This research study was designed to test the impact of Prolibra, a dairy-derived ingredient containing whey proteins, peptides and milk minerals, on weight loss, fat loss and lean muscle retention in obese individuals. Our hypothesis was that by purifying the active ingredients from milk (high leucine proteins, peptides and milk minerals) a supplement could be developed that would have a positive impact on fat loss, aid in retaining lean muscle and retain bone mineral content without needing to increase dietary protein intake above the recommended RDI (0.8 g/kg/day). The objective of the trial was to evaluate the effect of a Prolibra beverage on weight loss, body composition and anthropometric measurements over a 12-week period compared to a control beverage.