High Amounts of Exercise Are Associated with an Increased Preference for High‐Fat vs. Low‐Fat Food Choices

Abstract

Exercise suppresses appetite and reduces calorie intake over the short‐term, but the long‐term consequences of exercise on food intake, and in particular those on food choices, remain unclear. Previous research suggests that people who are moderately active tend to consume fewer calories than those who are inactive, but very high activity levels are associated with increased calorie consumption. Little work has been done to investigate whether actual food choices are also impacted by exercise.PURPOSETo determine the relationship between habitual exercise and decision making about food choices.METHODSA total of 104 participants (age: 20.1±2.7 y; BMI: 25.1±5.1 kg/m2; 79% female) conducted an electronic survey involving a series of binary choices among food options with varying rewarding properties, such as high or low fat content and/or sweet or non‐sweet foods. Participants were asked to make hypothetical choices for immediate consumption and between one option for immediate consumption and another option for delayed consumption (in 4h) and to indicate their relative preference for each food option (0–10 scale). Visual food cues were given with each question, and portion sizes were adjusted to approximately 350 kcal per item. Participants further completed an exercise and activity questionnaire and anthropometric data were collected upon completion of the survey. Participants were instructed to fast for ≥3h and to abstain from exercise all day prior to testing. Based on their habitual exercise, participants were classified either as non‐exercising (n=23) or divided into quartiles ranging from 1–2h/week (n=24), 2–4h/week (n=21), 4–6h/week (n=18), and >6 h/week (n=18).RESULTSWhen asked to make choices for immediate consumption, participants exercising >6h/week chose high‐fat over low‐fat options more than non‐exercisers (0.85±0.05 vs. 0.69±0.5, p=0.02). Participants exercising for 4–6h/week (0.59±0.05) or for >6h/week (0.61±0.05) chose sweet over non‐sweet options less than the non‐exercising group (0.74±0.05, both p≤0.05). When asked to choose between options for immediate over delayed consumption, participants exercising >6 h/week chose immediate high‐fat options over delayed low‐fat options more than non‐exercisers (0.81±0.06 vs. 0.65±0.05, p=0.04). There were no significant differences among groups regarding immediate low‐fat over delayed high‐fat choices and among immediate or delayed choices between sweet and non‐sweet options (all p>0.05). The overall preference for high‐fat foods was significantly lower (4.6±0.5 vs. 6.3±0.5, p=0.02) and the preference for low‐fat foods tended to be higher (7.4±0.4 vs. 6.5±0.3, p=0.08) among those who exercised >6 h/week when compared to non‐exercisers.CONCLUSIONOur results demonstrate a differential association between habitual exercising and food choices. Despite lower overall preferences for high‐fat foods, participants at the upper end of the exercise spectrum were more likely to choose high‐fat over low‐fat options, suggesting a higher preference for highly‐rewarding foods and/or compensatory mechanisms to meet the increased energy requirements of exercise. Interestingly, higher amounts of habitual exercise were associated with a lower likelihood to choose sweet options. Future research is needed to determine physiologic and behavioral mechanisms underlying the relationship between habitual exercise and food choices.Support or Funding InformationThe project was supported by a University of Nebraska Food for Health Initiative grant.