A significant contributor to the rising rates of @entity1 @entity28 is an increase in energy intake. The 'protein leverage hypothesis' proposes that a dominant appetite for protein in conjunction with a decline in the ratio of protein to fat and @entity1735 in the diet drives excess energy intake and could therefore promote the development of @entity28 . Our aim was to test the 'protein leverage hypothesis' in lean @entity1 by disguising the macronutrient composition of foods offered to subjects under ad libitum feeding conditions. Energy intakes and hunger ratings were measured for 22 lean subjects studied over three 4-day periods of in-house dietary manipulation. Subjects were restricted to fixed menus in random order comprising 28 foods designed to be similar in @entity2419 , availability, variety and sensory quality and providing 10%, 15% or 25% energy as protein. Nutrient and energy intake was calculated as the product of the amount of each food eaten and its composition. Lowering the percent protein of the diet from 15% to 10% resulted in higher (+12  4.5%, p=0.02) total energy intake, predominantly from savoury-flavoured foods available between meals. This increased energy intake was not sufficient to maintain protein intake constant, indicating that protein leverage is incomplete. Urinary @entity1133 on the 10% and 15% protein diets did not differ statistically, nor did they differ from habitual values prior to the study. In contrast, increasing protein from 15% to 25% did not alter energy intake. On the fourth day of the trial, however, there was a greater increase in the hunger score between 1-2 h after the 10% protein breakfast versus the 25% protein breakfast (1.6  0.4 vs 25%: 0.5  0.3, p=0.005). In our study population a change in the nutritional environment that dilutes dietary protein with @entity1735 and fat promotes overconsumption, enhancing the risk for potential @entity1017 .

Testing protein leverage in lean XXXX : a randomised controlled experimental study.

@entity1 :: ('9606', 'Species') :: ['humans', 'human'] @entity28 :: ('MESH:D009765', 'Disease') :: ['obesity'] @entity1133 :: ('MESH:D014508', 'Chemical') :: ['urea'] @entity1735 :: ('CHEBI:16646', 'Chemical') :: ['carbohydrate'] @entity1017 :: ('MESH:D015430', 'Disease') :: ['weight gain'] @entity2419 :: ('MESH:D002972', 'Disease') :: ['palatability']
@entity1 :: (9606,Species) :: ['humans']
