Just thinking about exercise makes me serve more food. Physical activity and calorie compensation
Werle, Carolina, Brian Wansink, and Collin Payne (2010). Just Thinking about Exercise Makes Me Serve More Food. Physical Activity and Calorie Compensation. Appetite, 56(2), 332-335. doi: 10.1016/j.appet.2010.12.016.
Introducing a new exercise routine may not result in the desired weight loss because people engage in more indulgent eating behaviors as a means of compensation. In this study we went a step further to explore if merely the thought of exercise could induce increased consumption in food. Furthermore, we wanted to determine if framing exercise as a fun activity would reduce this effect.
To test this, we recruited 94 adults at a mall under the guise that it was a study about shopping attitudes. There were three conditions. In the “exercise condition”, participants were asked about their exercise habits, and then were told to read a scenario describing a 30-minute run and how tired it made them feel. After reading the scenario they were asked to answer a few more questions. Once they were done and as a token of appreciation they were offered two types of snacks (Chex Mix and M&M’s) of they could serve themselves as much as they wanted. This procedure was repeated for participants in the “fun condition” except they were asked questions about their music habits and then asked to read a scenario describing a 30-min walk where the person was listening to music through their MP3 player. In the “control condition” participants did not have to read a scenario or answer any additional questions. All participants were asked to estimate the calories in the amount of snacks they had taken.
Overall, reading about physical activity caused participants to serve themselves a significantly more snacks. In the fun or exercise condition, participants poured 58.9% more M&M’s and 51.9% more Chex Mix. Although not statistically significant, results indicated that participants in the two exercise conditions were more biased in their calorie estimates.
This study has important implications for health professionals whose advice can be easily compromised by the potential impact of compensation. Perhaps presenting exercise as a critical way to tone one’s self as opposed to weight loss, may decouple the compensation link between exercise and eating.