A plant-based meal affects thalamus perfusion differently than an energy- and macronutrient-matched conventional meal in men with type 2 diabetes, overweight/obese, and healthy men: A three-group randomized crossover study

Abstract

Background & aims: Reward circuitry in the brain plays a key role in weight regulation. We tested the effects of a plant-based meal on these brain regions. Methods: A randomized crossover design was used to test the effects of two energy-and macronutrientmatched meals: a vegan (V-meal) and a conventional meat (M-meal) on brain activity, gastrointestinal hormones, and satiety in participants with type 2 diabetes (T2D; n ¼ 20), overweight/obese participants (O; n ¼ 20), and healthy controls (H; n ¼ 20). Brain perfusion was measured, using arterial spin labeling functional brain imaging; satiety was assessed using a visual analogue scale; and plasma concentrations of gut hormones were determined at 0 and 180 min. Repeated-measures ANOVA was used for statistical analysis. Bonferroni correction for multiple comparisons was applied. The Hedge's g statistic was used to measure the effect size for means of paired difference between the times (180-0 min) and meal types (MÀV meal) for each group. Results: Thalamus perfusion was the highest in patients with T2D and the lowest in overweight/obese individuals (p ¼ 0.001). Thalamus perfusion decreased significantly after ingestion of the M-meal in men with T2D (p ¼ 0.04) and overweight/obese men (p ¼ 0.004), and it decreased significantly after ingestion of the V-meal in healthy controls (p < 0.001; Group x Meal x Time: F ¼ 3.4; p ¼ 0.035). The effect size was À0.41 (95% CI, À1.14 to 0.31; p ¼ 0.26) for men with diabetes; À0.72 (95% CI, À1.48 to 0.01; p ¼ 0.05) for overweight/obese men; and 0.82 (95% CI, 0.09 to 1.59; p ¼ 0.03) for healthy men. Postprandial secretion of active GLP-1 increased after the V-meal compared with the M-meal by 42% (95% CI 25e62%; p ¼ 0.003) in men with T2D and by 41% (95% CI 24e61%; p ¼ 0.002) in healthy controls. Changes in thalamus perfusion after ingestion of both test meals correlated with changes in satiety (r ¼ þ0.68; p < 0.01), fasting plasma insulin (r ¼ þ0.40; p < 0.01), C-peptide (r ¼ þ0.48; p < 0.01) and amylin (r ¼ þ0.55; p < 0.01), and insulin secretion at 5 mmol/l (r ¼ þ0.77; p < 0.05). Conclusions: The higher postprandial GLP-1 secretion after the V-meal in men with T2D, with concomitant greater satiety and changes in thalamus perfusion, suggest a potential use of plant-based meals in addressing the key pathophysiologic mechanisms of food intake regulation. Trial registration ClinicalTrials.gov number, NCT02474147.

Plant-Based Diet as a Strategy for Weight Control

“…In the last decade, vegan and plant-based diets have been consistently associated with reduced body weight and other health benefits [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 ]. These diets are adopted by people mainly for health, environmental, and ethical reasons [ 21 , 22 ].…”

“…Although current scientific data suggest that limiting the consumption of meat and dairy products may contribute to better overall health, randomized clinical trials investigating the link between plant-based diets and human well-being are limited. However, plant-based diets, and especially vegan diets, may provide many benefits not only for overweight and obese individuals but also for individuals with type 2 diabetes, CHD, or arthritis [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 ]. It is highly likely that in the next few years, plant-based diets may be included in some guidelines for preventing and treating cardiovascular diseases, diabetes, and obesity.…”

A Plant-Based Meal Reduces Postprandial Oxidative and Dicarbonyl Stress in Men with Diabetes or Obesity more than an Energy- and Macronutrient-Matched Conventional Meal in a Randomized Crossover Study

“…The methods have beedn described in detail previously [14]. Brein y: This randomised crossover study group included 20 men with T2D, 20 obese men and 20 healthy men.…”

“…Availability of data and materials: The deidenti ed data will be available upon request at hkahleova@pcrm.org Competing Interests: No con ict of interest related to this manuscript has been reported. The postprandial state was measured after intake of a standard breakfast -one of two energy-and macronutrient-matched meals in a random order: either a plant-based meal (V-meal; tofu burger with spices, ketchup, mustard, tomato, lettuce and cucumber in a wheat bun) together with 300mL of green tea, or a conventional meat meal (M-meal; cooked-pork seasoned meat in a wheat bun, tomato, cheddartype cheese, lettuce, spicy sauce) together with 300 mL Café Latte [14].…”

“…Another study found improvements in postprandial incretin and insulin secretion after a plant-based meal in T2D patients, highlighting the therapeutic potential of this type of diet in improving b-cell function [13]. In this secondary analysis of previously published data [14], we have tested postprandial response to a plant-based meal compared with an energy-and macronutrient-matched conventional meal on oxidative and dicarbonyl stress, in ammation and appetite hormones in T2D and obese patients. Our hypothesis was that a plant-based meal would stimulate postprandial appetite hormones secretion and produce lower postprandial response of oxidative and dicarbonyl stress compared to the conventional meal.…”