Experiencing a stressful situation and then eating a high-fat meal the next day can slow down the body’s metabolism, potentially contributing to weight gain, according to a new study in women published in the journal Biological Psychiatry.
“This means that, over time, stressors could lead to weight gain,” said lead author Dr. Jan Kiecolt-Glaser, professor of psychiatry and psychology at Ohio State University.
“We know from other data that we’re more likely to eat the wrong foods when we’re stressed, and our data say that when we eat the wrong foods, weight gain becomes more likely because we are burning fewer calories.”
For the study, 58 women (average age 53) answered questions about the previous day’s stressors before eating a meal consisting of 930 calories and 60 grams of fat. The researchers then measured the participants’ metabolic rates — how long it took the women to burn calories and fat — and measured blood sugar levels, triglycerides, insulin, and the stress hormone cortisol.
In general, participants who reported that they had experienced one or more stressful events during the previous 24 hours burned 104 fewer calories than non-stressed participants in the seven hours after eating the high-fat meal. This difference could result in a weight gain of almost 11 pounds per year.
Most of the reported stressful situations were interpersonal in nature: arguments with co-workers, spouses or friends, trouble with children, or work-related pressures.
The stressed women showed higher levels of insulin, which contributes to the storage of fat and less fat oxidation — the conversion of fat molecules into fuel. Fat that is not burned is stored.
Prior research has shown that people who experience stress and other mood problems are at higher risk of becoming overweight. These findings appear to explain at least one reason for that connection.
The research meal consisted of eggs, turkey sausage, biscuits, and gravy — approximately the same amount of calories and fat found in a loaded two-patty hamburger and French fries from a fast-food restaurant.
“This is not an extraordinary meal compared to what many of us would grab when we’re in a hurry and out getting some food,” said Kiecolt-Glaser, also director of the Institute for Behavioral Medicine at Ohio State.
The control for comparison in this study was that one meal contained saturated fat and the other was high in monounsaturated fat (from sunflower oil).
“We suspected that the saturated fat would have a worse impact on metabolism in women, but in our findings, both high-fat meals consistently showed the same results in terms of how stressors could affect their energy expenditure,” said co-author Dr. Martha Belury, professor of human nutrition at Ohio State.
The researchers found that insulin spiked soon after the high-fat meal was consumed. It then decreased to roughly match insulin levels in non-stressed women after another 90 minutes.
A history of depression alone did not affect metabolic rate, but depression combined with a stressful situation led to a sharper increase in triglycerides after the meal. Triglycerides are a form of fat in the blood, and high levels are considered a risk for cardiovascular disease.
“With depression, we found there was an additional layer. In women who had stress the day before and a history of depression, triglycerides after the meal peaked the highest,” Kiecolt-Glaser said.
“The double whammy of past depression as well as daily stressors was a really bad combination.”
The researchers are reluctant to extend these findings to men since men tend to have more muscle than women, which affects their metabolic rates, Belury said.
Source: Ohio State University