Impact of Protein Content of Ultraprocessed Foods on the Regulation of Energy Balance

Impact of Protein Content of Ultraprocessed Foods on the Regulation of Energy Balance (ad Libitum Energy Intake and Energy Expenditure)

Aim of the study is to investigate the effects of high-protein, ultraprocessed foods on the regulation of energy balance in a metabolic chamber. The primary outcome parameter of the study is the energy balance (ad libitum energy intake and energy expenditure).

Each of the two study weeks starts with a 3-day run-in period with controlled diet at home, following 48 hours in a metabolic chamber. On the day the participants leave the metabolic chamber, they keep a food record over the rest of the day at home.

1. week: meals containing 30 % protein (80 % ultraprocessed high-protein foods), physical activity level (PAL) 1.45, 2 intervention days in the metabolic chamber: ad libitum energy intake
2. week: meals containing 13 % protein (80 % ultraprocessed foods with moderate protein content), physical activity level (PAL) 1.45, 2 intervention days in the metabolic chamber: ad libitum energy intake

Inclusion Criteria:

• healthy
• BMI 19-29 kg/m2
• low-medium habitual physical activity
• women with regular menstrual cycle (during intervention in follicular phase)

Exclusion Criteria:

• smoking
• chronic illnesses (e.g. renal dysfunction)
• regular intake of medication
• food allergies / intolerances
• vegans and vegetarians
• regular high physical activity (exercise >1 hour/d)
• current weight loss diet / weight loss of >5 kg in the last 3 months
• pregnant / lactating women
• persons incapable of giving informed legal consent
• restraint eaters (according to the German version of the 'Three-Factor-Eating-Questionnaire', Stunkard und Messick (1985))