Whey Protein & Weight Loss

The role of dairy foods in weight management.
Zemel MB. (2005)

Whey proteins in the regulation of food intake and satiety.
Luhovyy BL, et al. (2007)

Effect of a hypocaloric diet, increased protein intake and resistance training on lean mass gains and fat mass loss in overweight police officers.
Demling RH, DeSanti L. (2000)

The role of dairy foods in weight management.

Journal: J Am Coll Nutr. 2005 Dec;24(6 Suppl):537S-46S.

Authors: Zemel MB.

The University of Tennessee, 1215 W. Cumberland Ave, Room 229, Knoxville, TN 37996-1920, USA. mzemel@utk.edu

Abstract: Dietary calcium appears to play a pivotal role in the regulation of energy metabolism and obesity risk. High calcium diets attenuate body fat accumulation and weight gain during periods of over-consumption of an energy-dense diet and to increase fat breakdown and preserve metabolism during caloric restriction, thereby markedly accelerating weight and fat loss. This effect is mediated primarily by circulating calcitriol, which regulates adipocyte intracellular Ca(2+). Studies of human adipocyte metabolism demonstrate a key role for intracellular Ca(2+) in regulating lipid metabolism and triglyceride storage, with increased intracellular Ca(2+) resulting in stimulation of lipogenic gene expression and lipogenesis and suppression of lipolysis, resulting in adipocyte lipid filling and increased adiposity. Moreover, the increased calcitriol produced in response to low calcium diets stimulates adipocyte Ca(2+) influx and, consequently, promotes adiposity, while higher calcium diets inhibit lipogenesis, promote lipolysis, lipid oxidation and thermogenesis and inhibit diet-induced obesity in mice. Notably, dairy sources of calcium exert markedly greater effects in attenuating weight and fat gain and accelerating fat loss. This augmented effect of dairy products versus supplemental calcium has been localized, in part, to the whey fraction of dairy and is likely due to additional bioactive compounds, such as angiotensin converting enzyme (ACE) inhibitors in dairy, as well as the rich concentration of branched chain amino acids, which act synergistically with calcium to attenuate adiposity; however, these compounds do not fully account for the observed effects, as whey has significantly greater bioactivity than found in these compounds. These concepts are confirmed by epidemiological data as well as recent clinical trials which demonstrate that diets which include at least three daily servings of dairy products result in significant reductions in body fat mass in obese humans in the absence of caloric restriction and markedly accelerates the weight and body fat loss secondary to caloric restriction compared to low dairy diets. These data indicate an important role for dairy products in both the ability to maintain a healthy weight and the management of overweight and obesity.

Whey proteins in the regulation of food intake and satiety.

Journal: J Am Coll Nutr. 2007 Dec;26(6):704S-12S.

Authors: Luhovyy BL, Akhavan T, Anderson GH.

Department of Nutritional Sciences, University of Toronto, Rm 329, FitzGerald Building, 150 College St, Toronto, Ontario, Canada. bohdan.luhovyy@utoronto.ca

Abstract:

Whey protein has potential as a functional food component to contribute to the regulation of body weight by providing satiety signals that affect both short-term and long-term food intake regulation. Because whey is an inexpensive source of high nutritional quality protein, the utilization of whey as a physiologically functional food ingredient for weight management is of current interest. At present, the role of individual whey proteins and peptides in contributing to food intake regulation has not been fully defined. However, Whey protein reduces short-term food intake relative to placebo, carbohydrate and other proteins. Whey protein affects satiation and satiety by the actions of: (1) whey protein fractions per se; (2) bioactive peptides; (3) amino-acids released after digestion; (4) combined action of whey protein and/or peptides and/or amino acids with other milk constituents. Whey ingestion activates many components of the food intake regulatory system. Whey protein is insulinotropic, and whey-born peptides affect the renin-angiotensin system. Therefore whey protein has potential as physiologically functional food component for persons with obesity and its co-morbidities (hypertension, type II diabetes, hyper- and dislipidemia). It remains unclear, however, if the favourable effects of whey on food intake, subjective satiety and intake regulatory mechanisms in humans are obtained from usual serving sizes of dairy products. The effects described have been observed in short-term experiments and when whey is consumed in much higher amounts.

Effect of a hypocaloric diet, increased protein intake and resistance training on lean mass gains and fat mass loss in overweight police officers.

Journal: Ann Nutr Metab. 2000;44(1):21-9.

Authors: Demling RH, DeSanti L.

Brigham and Women's Hospital, Boston, MA 02115, USA. rhdemling@partners.org

Abstract: We compare the effects of a moderate hypocaloric, high-protein diet and resistance training, using two different protein supplements, versus hypocaloric diet alone on body compositional changes in overweight police officers. A randomized, prospective 12-week study was performed comparing the changes in body composition produced by three different treatment modalities in three study groups. One group (n = 10) was placed on a nonlipogenic, hypocaloric diet alone (80% of predicted needs). A second group (n = 14) was placed on the hypocaloric diet plus resistance exercise plus a high-protein intake (1.5 g/kg/day) using a casein protein hydrolysate. In the third group (n = 14) treatment was identical to the second, except for the use of a whey protein hydrolysate. We found that weight loss was approximately 2.5 kg in all three groups. Mean percent body fat with diet alone decreased from a baseline of 27 +/- 1.8 to 25 +/- 1.3% at 12 weeks. With diet, exercise and casein the decrease was from 26 +/- 1.7 to 18 +/- 1.1% and with diet, exercise and whey protein the decrease was from 27 +/- 1.6 to 23 +/- 1.3%. The mean fat loss was 2. 5 +/- 0.6, 7.0 +/- 2.1 and 4.2 +/- 0.9 kg in the three groups, respectively. Lean mass gains in the three groups did not change for diet alone, versus gains of 4 +/- 1.4 and 2 +/- 0.7 kg in the casein and whey groups, respectively. Mean increase in strength for chest, shoulder and legs was 59 +/- 9% for casein and 29 +/- 9% for whey, a significant group difference. This significant difference in body composition and strength is likely due to improved nitrogen retention and overall anticatabolic effects caused by the peptide components of the casein hydrolysate.