Purified egg protein supplementation has beneficial effects on body composition, metabolism and eating behavior and results in a more sustained weight loss than low fat diet

Abstract

Background: An increasing body of literature emphasizes the interest of moderate enrichment in protein for treating obesity and its metabolic consequences. However, egg proteins that are known to have the highest biological value have not been studied in this context. We investigated in self-restricted obese individuals with low Protein Intake (PI) (< 0.7 g.kg -1 .d -1 ) the effects of increasing PI up to 1.5 g.kg -1 .d -1 on body weight, body composition, eating behavior, Resting Metabolic Rate (RMR) and kidney function.Randomized controlled trial over 2 months: Twelve subjects were given daily supplements of a formula of Purified high biological value Egg Protein (PEP) (Ovamine ® Nutreven laboratories, Paris) to achieve this level of PI while ten matched controls were given a simple Low-Fat High Protein Diet (LFHPD). Subjects were tested before and after 2 months. PEP resulted in increased PI (1.39 ± 0.07 vs 0.65 ± 0.07 g.kg -1 .d -1 p < 0.01), higher percentage of protein (+9.6%, p < 0.01) and lower percentage of lipids (-13,6%, p < 0.01) in diet, while these values were not significantly modified with LFHPD. Analogic-numeric scales indicated that appetite increased under LFHPD and decreased under PEP (p = 0.006) with a subjective feeling of eating less (p < 0.01), yet in both groups, total calculated energy intake was not decreased. Under PEP (but not LFHPD) there was a decrease in weight (-1.97 ± 0.5 kg p < 0.01) and body mass index (-0.74 ± 0,18%, p < 0.01) due to a decrease in fat mass only (-3.2 ± 1.3 kg p < 0,05). There was in both groups a nonsignificant tendency to reduce RMR with no change in RER. Creatinine clearance increased by 10% under PEP (before: 149 ± 19; after: 162 ± 22 ml.min -1 , p = 0.05) but not under LFHPD. Microalbuminuria was unchanged.Controlled follow-up trial over 18 months: 337 subjects divided into three matched groups followed over 18 months: no change in diet or lifestyle (n = 69); LFD (n = 171), and PEP (n = 97) targeting 1.2 g.kg -1 .d -1 protein with the same purified egg protein preparation of high biological value. In the group of control subjects (n = 58) there was a gradual weight increase up to +8.58 ± 0.56 % of initial weight on the 18th month, while subjects on low fat diet had lost -5.55 ± 1.31 and those receiving moderate enrichment in protein had lost -8.07 ± 1.58. The initial drop-out at 1 month is -19% with low fat diet and -15% with moderate enrichment in protein. After 6 months it is -57% with low fat diet and -47% with moderate enrichment in protein. During the first 6 months the curves of low-fat diet and protein supplementation are almost overlapped but after 8 months the difference becomes significant. At 18 months, subjects on low fat diet have lost -5.95 ± 1.82 and those receiving moderate enrichment in protein have lost -8.05 ± 1.87 (p = 0.023). On the whole moderate enrichment in protein induces a weight loss > 10% in 18% of the subjects and a weight loss > 5-10 in 22% of them. Visual analogic scales evidence in receiving egg protein a decrease in appeti...