Speed Limits: Food Intake and Eating Behaviour of Ultra-processed and Unprocessed Foods

Rationale: Foods that can be eaten at a fast rate - with low mastication effort - lead to shorter orosensory exposure (OSE) per unit of food consumed. This results in a decreased satiation response and higher subsequent food intake. Recent research has shown that participants on a ultra-processed diet have an higher caloric intake and gain body weight compared to those on an unprocessed food diet. In this study the ultra-processed vs. unprocessed meals were classified according to the NOVA classification and matched on caloric content and palatability. The NOVA classification, classifies foods based on the physical, biological and chemical processes that occur after foods are separated from nature, and before they are consumed or used in the preparation of dishes and meals. However, it remains unclear whether the found increase in food intake of ultra-processed foods is due to industrial processing or because of a difference in eating rate at which the (ultra-)processed foods can be consumed. Objective: The objective of this study is to determine the independent and additive effects of industrial food processing (according to the NOVA classification) and eating rate on satiation. Study design: The study has a 2x2 randomized crossover design. All participants receive 4 treatments and are their own control. Study population: Healthy adults (n=60) between 18-55 years old with a BMI between 18.5-27 kg/m2. Intervention: Participants will join 4 test days during which they receive 3 main test meals (breakfast, lunch, dinner) and in-between meals snacks according to one of the 4 diets. The 4 diets of this study are: 1) unprocessed, slow eating rate 2) unprocessed, fast eating rate 3) ultra-processed, slow eating rate 4) ultra- processed, fast eating rate. During eating and before and after eating the weight of the plate will be measured to determine intake. Additionally, participants will be recorded on video to determine eating behaviour (number of bites, chews and o