title: Protein leverage and energy intake.
abstract: Increased energy intakes are contributing to overweight and obesity. Growing evidence supports the role of protein appetite in driving excess intake when dietary protein is diluted (the protein leverage hypothesis). Understanding the interactions between dietary macronutrient balance and nutrient-specific appetite systems will be required for designing dietary interventions that work with, rather than against, basic regulatory physiology. Data were collected from 38 published experimental trials measuring ad libitum intake in subjects confined to menus differing in macronutrient composition. Collectively, these trials encompassed considerable variation in percent protein (spanning 8-54% of total energy), carbohydrate (1.6-72%) and fat (11-66%). The data provide an opportunity to describe the individual and interactive effects of dietary protein, carbohydrate and fat on the control of total energy intake. Percent dietary protein was negatively associated with total energy intake (F = 6.9, P < 0.0001) irrespective of whether carbohydrate (F = 0, P = 0.7) or fat (F = 0, P = 0.5) were the diluents of protein. The analysis strongly supports a role for protein leverage in lean, overweight and obese humans. A better appreciation of the targets and regulatory priorities for protein, carbohydrate and fat intake will inform the design of effective and health-promoting weight loss diets, food labelling policies, food production systems and regulatory frameworks.
authors.affiliation: Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia; School of Biological Sciences, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: A K
authors.initials: AK
authors.lastname: Gosby
authors.forename: A D
authors.initials: AD
authors.lastname: Conigrave
authors.forename: D
authors.initials: D
authors.lastname: Raubenheimer
authors.forename: S J
authors.initials: SJ
authors.lastname: Simpson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001066:Appetite; D015992:Body Mass Index; D002986:Clinical Trials as Topic; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000378:metabolism; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism; D004043:Dietary Fiber / Q000008:administration & dosage / Q000378:metabolism; D004044:Dietary Proteins / Q000008:administration & dosage / Q000378:metabolism*; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006304:Health Status; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000209:etiology / Q000517:prevention & control; D050177:Overweight / Q000209:etiology / Q000517:prevention & control; D015431:Weight Loss; D055815:Young Adult
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004043:Dietary Fiber; D004044:Dietary Proteins
keywords: Ad libitum; energy intake; macronutrient; obesity; protein leverage