The effect of protein status on food preferences and intake.

Rationale:

It has been posed that protein intake is tightly regulated in the human body. It has been shown that when subjects have eaten high-protein meals, a significantly greater reduction is seen in liking for high-protein food than for high-carbohydrate foods. In our previous research, we did not observe this effect within one meal. Animal and human studies suggest that energy and macronutrient balance are regulated over a longer period of time.



Objective:

To determine the effect of protein status on food preferences and intake.



Study design:

The study will consist of two 14-day fully controlled dietary interventions that involve consumption of individualized, isoenergetic menus providing either 0.5 g protein/kg BW/day (low protein diet), or 2.0 g protein/kg BW/day (high protein diet), using a randomized crossover design. The interventions will be followed by a 2-day ad libitum-phase, where protein intake (g) will be measured. Both interventions will be preceded by 2 days on which subjects eat a normal protein diet. The interventions will be separated by a minimum of 1 week washout.



Study population:

The study population will consist of 40 apparently healthy, unrestrained volunteers between the age of 18 and 35 with a normal weight.



Main study parameters/endpoints:

Our main outcome measurement is the difference between protein intake (g) during the 2-day ad libitum-phase following the two interventions.

The protein status of an individual effects food preferences and intake. If the protein status is high, choice and intake of high-protein foods will be decreased. If the protein status is low, choice and intake of high-protein foods will be increased.

Every participant will visit the laboratory every day during the intervention periods.

Two 14-day fully controlled intervention periods differing in dietary protein intake. These interventions involve consumption of individualized, iso-energetic menus providing either 0.5 g protein/kg bodyweight/day (low protein diet) or 2.0 g protein/kg bodyweight/day (high protein diet).