Meal Patterns and Food Choices of Female Rats Fed a Cafeteria-Style Diet Are Altered by Gastric Bypass Surgery.

Ginger D Blonde,Alan C Spector,Ruth K Price,Carel W Le Roux

doi:10.3390/nu13113856

Ginger D Blonde, Alan C Spector + Show 2 more

Open Access

https://doi.org/10.3390/nu13113856

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Abstract

After Roux-en-Y gastric bypass surgery (RYGB), rats tend to reduce consumption of high-sugar and/or high-fat foods over time. Here, we sought to investigate the behavioral mechanisms underlying these intake outcomes. Adult female rats were provided a cafeteria diet comprised of five palatable foodstuffs varying in sugar and fat content and intake was monitored continuously. Rats were then assigned to either RYGB, or one of two control (CTL) groups: sham surgery or a nonsurgical control group receiving the same prophylactic iron treatments as RYGB rats. Post-sur-gically, all rats consumed a large first meal of the cafeteria diet. After the first meal, RYGB rats reduced intake primarily by decreasing the meal sizes relative to CTL rats, ate meals more slowly, and displayed altered nycthemeral timing of intake yielding more daytime meals and fewer nighttime meals. Collectively, these meal patterns indicate that despite being motivated to consume a cafeteria diet after RYGB, rats rapidly learn to modify eating behaviors to consume foods more slowly across the entire day. RYGB rats also altered food preferences, but more slowly than the changes in meal patterns, and ate proportionally more energy from complex carbohydrates and protein and proportionally less fat. Overall, the pattern of results suggests that after RYGB rats quickly learn to adjust their size, eating rate, and distribution of meals without altering meal number and to shift their macronutrient intake away from fat; these changes appear to be more related to postingestive events than to a fundamental decline in the palatability of food choices.

Highlights

While self-reporting methods of measuring food intake have utility, they are vulnerable to mis-reporting, under-reporting and are unlikely to be representative of usual food intake [23,24,25]
Food preferences changed more slowly across multiple days to reduce intake of fat but rats continued to consume most of their energy from foods high in fat and/or sugar. These results suggest that when provided the opportunity to self-select foods, rats continue to be motivated to consume fat and sugar but instead adapt intake behaviors to Nutrients 2021, 13, 3856 more evenly spread energy consumption across the day, possibly in an attempt to avoid negative post-ingestive consequences of eating too much at one time
When the animals were moved to the full array of foods in the cafeteria diet, rats consumed the least energy on the first day

Summary

Introduction

The procedure results in a substantial loss of body mass, which is maintained for many years along with the mitigation of typical obesity-associated comorbidities such as cancer, cardiovascular disease, and Type II diabetes mellitus [1,2,3,4,5,6,7,8,9,10,11]. The success of this surgery is often credited to the overall reduction in food intake. A recent study found that when food choice and intake were measured directly in a buffet meal, patients with RYGB decreased their energy intake, but did not change their relative consumption of energy-dense foods. [3,26,27,28,29]

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