A randomised controlled trial investigating the influences of food form and energy density on appetite, satiation and satiety in healthy adults

Background: Texture and energy density are two physical properties of foods known to impact on eating behaviour. For those with mastication and/or deglutition disorders; diets which have their texture altered are prescribed. Further these texture modified diets may be energy enriched in an effort to optimise the opportunity for individuals prescribed them to meet their required energy intakes. However there is insufficient evidence supporting this strategy. No well controlled studies have been conducted evaluating these alterations (made in line with clinical guidelines), which specifically investigates their impact on eating behaviour. As such despite their intention to facilitate food and energy intakes it is unknown if these diets are in fact fit for purpose. Objective: To investigate the effect of texture modification, and/or energy enrichment of a standard meal developed to meet current recommendations for meal provision in hospitals on appetite parameters and food and energy intakes at a single eating occasion, in healthy adults. Design: A single blind, randomised crossover within-subjects design, where on four occasions 33 healthy adults consumed a test meal at lunch until satiation (i.e. meal termination) was reached whilst rating their appetite parameters. The meal had its texture and/or energy density altered to compare the effects of food form and energy density on appetite and satiation. The quantity of meal consumed was calculated using a plate wastage method. Subsequent intakes were recorded in a food diary to determine the effect of the treatments on satiety and identify any evidence of energy compensation. Food (g) and energy intakes (kcal) consumed during the feeding session were analysed using repeated measures ANOVA. Results: Test meal energy intakes (kcal) were significantly higher with energy enrichment of both meals (standard texture (ST); 315 kcal and texture modified (TM); 303 kcal (p=0.001)). Area under the curve (AUC) did not differ between meals for hunger, fullness, or desire to eat however palatability was significantly reduced with texture modification. Regardless of the composition and quantity consumed at the test meal, post-meal energy and macronutrient intakes remained the same across all days. Evidence of partial energy compensation was revealed (15 % (ST) and 22% (TM)) thus energy intakes remained higher over the day for both (260 kcal and 225 kcal respectively) (p<0.05). Conclusions: Enriching a meal, suitable for provision in a hospital setting results in significantly greater energy content without impacting on rated palatability. In a well-controlled, healthy sample, this enriched meal was sufficient to increase energy intakes (kcal) at an individual eating occasion for both ST and TM meals without affecting absolute food intake (g) or appetite responses (between meals) at the testing session. Incomplete subsequent energy compensation resulted in daily energy intakes remaining significantly higher with consumption of the enriched meals. Thus energy enrichment at a single meal, appropriate for provision for patients requiring a “Texture C” diet appears to be a suitable method to optimise short term energy intakes, in a healthy sample not confounded by disease state. Further investigation into enrichment of these meals in a clinical setting is justified.