How does eating breakfast affect fat cells in lean people? How about the fat cells in those with obesity? New research explores this by looking at the metabolic effects of eating — and skipping — breakfast.
Does breakfast help you to lose weight, or does it have the opposite effect? Here at Medical News Today, we have been reporting on conflicting studies in this regard.
For instance, one large population study that we covered suggests that a large breakfast helps us to avoid snacking during the day, which keeps weight gain at bay.
Another study, on the other hand, suggests that skipping breakfast does nothing to affect our calorie intake throughout the day.
But most of these studies are observational and cannot tell us much about the mechanisms behind weight loss, our metabolism, and breakfast eating. A new study, however — which has just been published in the Journal of Physiology — examines precisely such mechanisms.
The research, which was led by Javier Gonzalez, Ph.D., at the University of Bath in the United Kingdom, examines how breakfast affects the metabolism and fat cells of lean and obese individuals.
Lean people benefit from skipping breakfast
Gonzalez and team asked 49 adult participants to either have breakfast or fast until noon, every day, for 6 weeks.
Of the participants, 29 were classified as "lean" and 20 as "obese," according to their body mass index (BMI). The participants in the breakfast group consumed 350 kilocalories within 2 hours of waking up, while those in the fasting group had no energy intake until noon.
Both before and after the intervention, the team examined the patients' markers of cardiometabolic health, their appetite responses, and their body fat distribution.
In addition, they monitored the activity of 44 genes regulating key proteins, and the fat cells' ability to use glucose in response to insulin.
In lean people, skipping breakfast for 6 weeks increased the activity of genes that helped to burn fat, therefore improving metabolism. However, this effect was not seen in obese adults.
This new study revealed that in obese individuals, the fat cells could not take up as much glucose in response to insulin as lean individuals did. This effect seemed to be proportional to the individual's whole-body fat.
The researchers think that this is an adaptive mechanism in people with obesity, in which their body is trying to limit the amount of glucose their fat cells can take, so that it avoids storing additional fat.
"[B]y better understanding how fat responds to what and when we eat," says Gonzalez, "we can more precisely target those mechanisms. We may be able to uncover new ways to prevent the negative consequences of having a large amount of body fat, even if we cannot get rid of it."
He also lays out some limitations of the study, saying, "Since participants ate high-carb breakfasts, we cannot necessarily extrapolate our findings to other types of breakfasts, particularly those with high protein content."
"Our future studies will also explore how breakfast interacts with other lifestyle factors such as exercise," adds Gonzalez.