If you're finding it difficult to lose weight, your stress levels may be to blame.
A new study has found that chronic stress stimulates the production of a protein called betatrophin, which reduces our ability to break down fat.
As a result, weight loss becomes more difficult - even if you are trying hard to eat healthy food.
While the study only analysed the links between betatrophin and weight loss/gain in mice, the authors said the findings may provide an insight into why some people find weight loss harder than others.
The researchers, from the University of Florida Health, found that high levels of betatrophin suppress an enzyme that breaks down stored fat called adipose triglyceride lipase.
Commenting on the findings, lead study author Li-Jun Yang confirmed: "Betatrophin reduces the body’s ability to break down fat, underscoring a link between chronic stress and weight gain."
The findings are published in the journal BBA Molecular and Cell Biology of Lipid.
This isn't the first study to suggest that our stress levels may have an impact on our weight.
Previous research from Ohio State University found that people who experienced regular stress at work or home produced higher levels of the hormone cortisol.
The researchers found that having high levels of cortisol made participants feel more hungry than others, leading to them consuming more food and gaining weight.
They also noted that cortisol is known to stimulate the deposit of fat around the stomach area.