Abstract
Background: The ability to consume a meal containing a higher proportion of vegetables that results in clinically significant reductions in energy intake would be of assistance in controlling body weight. In turn, this would aid in the prevention and management of obesity, type 2 diabetes mellitus and other obesity-related diseases. Of particular interest is the Diabetes New Zealand healthy plate model, which proposes one-half of the plate be vegetables, one-quarter starchy foods, and one-quarter protein foods.
Objective: To determine the effects of varying the proportions and types of starchy foods and non-starchy vegetables that comprise a mixed lunch meal on energy intake subsequently consumed after the meal for the remainder of the day, and total daily energy intake.
Methods: Eighty participants were randomised to consume three rice or three pasta-based meals in a crossover design on three separate occasions. The meals comprised 200 g of beef mince in bolognaise sauce with: 100 g of starchy food (rice or pasta) and 250 g of vegetables; 150 g of starchy food and 200 g of vegetables (the reference meal); or 200 g of starchy food and 150 g of vegetables. The total weight of food in each meal remained the same (550 g). Meals presented proportions on the plate equal to: one-quarter starchy food and one-half vegetables; equal amounts of starchy food and vegetables; one-half starchy food and one- quarter vegetables. Food and beverage intake was recorded over the entire day and subsequent energy intake was measured following lunch meal consumption for the remainder of that day (until 2359 hours).
Results: The energy content of the meals increased as the amount of starchy food within the meal increased (1808, 2030, and 2255 kJ for low, medium and high rice containing meals, respectively; and 1832, 2074, and 2316 kJ for low, medium and high pasta containing meals, respectively). There were no significant differences in subsequent and total daily energy intake between the rice and the pasta meals (p>0.05). Total daily energy intake was 7.3% (594 kJ) lower when the largest compared to the smallest vegetable containing meal was consumed (p=0.008). There were no significant differences in subsequent energy intake following test meal consumption and in energy intake preceding test meal consumption between the meals containing different proportions of starchy foods and non-starchy vegetables (p>0.05). The meal best visually representing the healthy plate model was the meal containing the highest proportion of vegetables and the lowest proportion of starchy foods.
Conclusion: A greater amount of non-starchy vegetables can partially replace the starchy proportion of a meal to reduce the energy content, with the potential to reduce subsequent energy intake and total daily energy intake. Following the Diabetes New Zealand healthy plate model is recommended to achieve such reductions in energy intake. The type of starchy food (pasta or rice) consumed within a meal does not influence subsequent energy intake, due to pasta and rice having a similar energy density; therefore, the type of starchy food consumed within a meal is up to individual preference.