According to their findings, it all comes down to blood sugar. Consumers who experience big dips in their blood sugar after eating are likely to feel hungrier throughout the day; this can often lead to overeating.
“It has long been suspected that blood sugar levels play an important role in controlling hunger, but the results from previous studies have been inconclusive,” said researcher Dr. Sarah Berry. “We’ve now shown that sugar dips are a better predictor of hunger and subsequent calorie intake than the initial blood sugar peak response after eating, changing how we think about the relationship between blood sugar levels and the food we eat.”
Monitoring dips in blood sugar
To understand what role blood sugar plays in regulating how often consumers feel hungry, the researchers had over 1,000 participants involved in the study. Over the course of two weeks, participants recorded how often they were hungry and what they were eating; they also wore monitors that tracked their blood sugar, sleep, and activity. Throughout the study, all participants ate the same breakfast but were free to make their own choices for lunch and dinner.
The researchers learned that dips in blood sugar played the biggest role in making the participants feel hungry more often. Experiencing sharp drops in blood sugar only a few hours after eating breakfast made the participants more likely to snack more between meals.
Participants with the biggest dips in blood sugar usually experienced them between two and four hours after eating breakfast. This made them eat lunch a half-hour earlier than participants with smaller dips in blood sugar, and they also consumed about 75 more calories between breakfast and lunch. Over the course of the whole day, these large spikes in blood sugar between meals led participants to eat an average of 300 additional calories.
When thinking about what this looks like over the course of a month or a year, the researchers explained that it could contribute to significant weight gain. Big spikes in blood sugar may be responsible for frequent snacking, and it can also impact consumers’ ability to lose weight.
“Many people struggle to lose weight and keep it off, and just a few hundred extra calories every day can add up to several pounds of weight gain over a year,” said researcher Ana Valdes. “Our discovery that the size of sugar dips after eating has such a big impact on hunger and appetite has great potential for helping people understand and control their weight and long-term health.”
Look for foods that keep you full
Moving forward, the researchers hope that consumers use these findings to their advantage. Everyone’s metabolism responds differently depending on what they eat each day, and knowing what foods will keep us full the longest is a good way to manage health and cut down on excessive eating.
“Food is complex and humans are complicated, but our research is finally starting to open up the black box between diet and health,” said researcher Tim Spector. “We’re excited to have been able to turn this cutting-edge science into an at-home nutrition and microbiome test so that everyone has the opportunity to discover their unique responses to food to best support their metabolism and gut health.”