Though the impact on energy intake of reducing energy density is well known, there is less scientific evidence on how changes in texture can lead to reductions in eating rate. Through mathematical modelling and a human intervention trial, "RESTRUCTURE: Developing and implementing innovative and evidence-based food design principles to moderate energy intake " will unravel the links between physical properties like food texture, the speed of eating and energy intake. 

The RESTRUCTURE project is a 5-year research programme co-financed by TKI Agri & Food, a Dutch funding scheme for public-private partnerships. This project contributes to the Dutch government’s mission to guide consumers to make healthy food choices (Mission D, MMIP D2, TKI) and increase the supply of healthier foods by the food industry, by implementing additional design principles based on texture and eating rate.

BACKGROUND of the project

In recent years, ultra-processed foods (UPF) have become one of the most discussed nutrition topics world-wide. Several studies have shown that diets high in UPFs are associated with overweight and obesity and diet-related chronic diseases such as type 2 diabetes and coronary heart disease. One randomized controlled trial has confirmed this finding where people consumed more energy and gained weight (~ 1 kg) on a two-week UPF diet compared to an unprocessed food diet. However, to date it is unknown what aspects of UPF drive this effect on calorie overconsumption and health

Based on previous research we know that certain food properties drive calorie consumption. Two of these important food properties are thought to be food texture (or structure such as liquid, soft, hard, elastic etc.) and energy density (the number of calories contained in 100 g of food), may make people eat more of them. 

Energy density affects how much calories people consume as people tend to eat a fixed amount or portion of a specific food, not adjusting for the amount of energy it may contain. For example, a person may commonly eat one bowl of yoghurt in the morning, when served a different type of yoghurt (with more calories) the person will not adjust the amount of yoghurt in the bowl accordingly and eat the amount or volume that he/she is used to while consuming more calories. Certain food textures require less chewing before a bite of food can be swallowed and are therefore faster to eat. 

Previous research has shown that the speed of eating affects the speed at which we feel full, which in turn determines how much food we eat during a meal. When food is eaten quickly, people tend to eat more. The texture of UPF may therefore play an important role in driving food or calorie overconsumption of these foods. Eating more calories than the body uses, needs to storage of energy in the form of bodyfat, leading to weight gain over time. For example, the image below shows that the same number of grapes is consumed 12 times faster when squeezed into a juice compared to when eaten as whole grapes. When eating the whole grapes, someone will most likely feel full far before finishing the entire portion of 1 kilogram. This shows that the type of food and the speed of eating may influence how much we consume of the food.