Shopping
Cart
Body Weight and Protein
The role of dietary protein in body weight regulation has been recently examined by several investigators. 1-4 Protein plays a key role in food intake and body composition regulation through its effects on satiety and diet-induced thermogenesis. It is known that protein is more satiating than both carbohydrate and fat in the short term, over 24 hours and in the long term.4 For instance, one investigator found that a high-protein weight-reduction diet may provide a more favorable cardiovascular risk profile than a low-protein diet with similar weight reduction in people with type 2 diabetes.3 Certainly, there is a growing body of evidence that suggest the isocaloric substitution of carbohydrate with protein produces favorable changes in body composition; however, new evidence shows that consuming extra protein after body weight loss may be an effective strategy in preventing or limiting weight regain.
In a randomized parallel design, 148 male and female subjects (age 44 years; body mass index (BMI) 29.5 kg/m2; body fat 37 %) followed a very low-energy diet (~500 kcal per day) during 4 weeks. For the next three months of weight-maintenance assessment, they were stratified according to age, BMI, body weight, restrained eating, and resting energy expenditure (REE), and randomized over two groups. Only one group received 48.2 g/day additional protein to their diet. Measurements at baseline, after weight loss, and after 3 months weight maintenance were body weight, body composition, metabolic measurements, appetite profile, eating attitude, and relevant blood parameters. They found that a 20% higher protein intake, that is, 18% of energy versus 15% of energy during weight maintenance after weight loss, resulted in a 50% lower body weight regain that consisted of fat-free mass. This was related to increased satiety and decreased energy efficiency.2
Another study used a randomized parallel study design that consisted of 113 overweight subjects (BMI 29 kg/m2; age 45 years) followed a very-low-energy diet for 4 weeks, after which there was a 6-month period of weight maintenance. During the weight maintenance period, subjects were randomly assigned into either a protein group or a control group. The protein group received 30 g/d protein in addition to their usual diet. The investigators found that during weight maintenance, the protein group showed a higher protein intake (18 % v. 15 % of calories), a lower weight regain, and a decreased waist circumference compared with the control group. Weight regain in the protein group consisted of only fat-free mass, whereas the control group gained fat mass as well. Satiety in the fasted state before breakfast increased significantly more in the protein group than in the control group.1
In summary, it is evident that the mere addition of protein (~30-50 grams per day) may be an effective strategy in limiting weight regain. Furthermore, any weight gain that may ensue is primarily fat-free mass. The mechanism for this may include improved satiety, enhanced diet-induced thermogenesis, and greater energy inefficiency; furthermore, there are no deleterious effects of the additional protein.4
References
1. Lejeune MP, Kovacs EM, Westerterp-Plantenga MS. Additional protein intake limits weight regain after weight loss in humans. Br J Nutr. Feb 2005;93(2):281-289.
2. Westerterp-Plantenga MS, Lejeune MP, Nijs I, van Ooijen M, Kovacs EM. High protein intake sustains weight maintenance after body weight loss in humans. Int J Obes Relat Metab Disord. Jan 2004;28(1):57-64.
3. Brinkworth GD, Noakes M, Parker B, Foster P, Clifton PM. Long-term effects of advice to consume a high-protein, low-fat diet, rather than a conventional weight-loss diet, in obese adults with type 2 diabetes: one-year follow-up of a randomised trial. Diabetologia. Oct 2004;47(10):1677-1686.
4. Westerterp-Plantenga MS. The significance of protein in food intake and body weight regulation. Curr Opin Clin Nutr Metab Care. Nov 2003;6(6):635-638.
window.print();