Dietary Protein, Weight Loss, and Weight Maintenance

Abstract

The role of dietary protein in weight loss and weight maintenance encompasses influences on crucial targets for body weight regulation, namely satiety, thermogenesis, energy efficiency, and body composition. Protein-induced satiety may be mainly due to oxidation of amino acids fed in excess, especially in diets with "incomplete" proteins. Protein-induced energy expenditure may be due to protein and urea synthesis and to gluconeogenesis; "complete" proteins having all essential amino acids show larger increases in energy expenditure than do lower-quality proteins. With respect to adverse effects, no protein-induced effects are observed on net bone balance or on calcium balance in young adults and elderly persons. Dietary protein even increases bone mineral mass and reduces incidence of osteoporotic fracture. During weight loss, nitrogen intake positively affects calcium balance and consequent preservation of bone mineral content. Sulphur-containing amino acids cause a blood pressure-raising effect by loss of nephron mass. Subjects with obesity, metabolic syndrome, and type 2 diabetes are particularly susceptible groups. This review provides an overview of how sustaining absolute protein intake affects metabolic targets for weight loss and weight maintenance during negative energy balance, i.e., sustaining satiety and energy expenditure and sparing fat-free mass, resulting in energy inefficiency. However, the long-term relationship between net protein synthesis and sparing fat-free mass remains to be elucidated.

Prospective associations of dietary insulin demand, glycemic index, and glycemic load during puberty with body composition in young adulthood

“…Intakes of carbohydrate, protein or fat were not considered because those macronutrients contribute to the dietary insulin index and insulin load. However, as protein may also conduce higher lean mass, 39 we included this macronutrient as a covariate in a further step (data not shown) and observed a similar association between higher dietary insulin index and insulin load during puberty, and higher %BF in young adulthood (insulin index: P for trend ¼ 0.0965; insulin load: P for trend ¼ 0.07).…”

“…In addition, further adjustment for protein enhanced the association between dietary insulin demand and body fat. This may reflect a bi-directional relevance of dietary protein, which may contribute to a higher lean body mass on the one hand 39 and a higher insulin secretion 17 or lower insulin clearance on the other hand. 48 The relationship between a higher dietary insulin demand during puberty and a higher %BF in young adulthood was attenuated by the additional consideration of baseline %BF.…”

Efficacy and consequences of very-high-protein diets for athletes and exercisers

“…Satiety was greater in the protein group than the habitual energy group (67) . Increased satiety has been shown to result from acute protein consumption and high-protein diets (69)(70)(71)(72) . Satiety measured in the postabsorptive state may be attributed to increased resting energy expenditure (68)(69)(70) .…”

Intake of total, animal and plant protein and subsequent changes in weight or waist circumference in European men and women: the Diogenes project

“…2,3 A comprehensive review from 2009, studying the epidemiological evidence on the associations between diet (both at macronutrient level and food level) and subsequent weight gain and obesity, however, concluded that based on the selected literature 'Levels of protein intake, regardless of source, are not associated with subsequent excess weight gain or obesity although the results were inconsistent'. 4 Among the eight cohort studies found on adults, six studies did not find any significant associations between total protein intake and subsequent changes in weight or waist circumference (WC).…”