The objective of this study is to determine ad libitum daily energy and protein intake, energy balance and appetite profile in response to protein/carbohydrate and fat ratio over 12 consecutive days, also as a function of age, gender, BMI and FTO polymorphisms.

Following the protein leverage hypothesis, energy intake may be a derivative of protein intake. Therefore, in response to an unbalanced menu relative to the usual daily intake target, protein intake should be prioritized. Individuals may over-consume carbohydrate and fat of a menu containing a lower ratio of protein to carbohydrate and fat until the daily intake target amount of protein is ingested, and not the target of total energy intake because of a deficit of protein intake. In contrast, individuals may under-consume energy when the menu has an increased protein to carbohydrate and fat ratio. The protein leverage hypothesis requires evidence for why protein intake is more important than carbohydrate or fat in relation to food intake regulation.

Inclusion Criteria:

• BMI 18-35 kg/m2
• age between 18-70 years
• healthy
• non-smoking
• not using a more than moderate amount of alcohol (> 10 consumptions/wk)
• weight stable (weight change < 3 kg during the last 6 months)
• not using medication or supplements except for oral contraceptives in women

Exclusion Criteria:

• not healthy
• smoking
• using a more than moderate amount of alcohol
• not being weight stable
• using medication or supplements except for oral contraceptives in women
• do not meet the criteria for BMI and age
• pregnant or lactating
• allergic for the used food items