In obese men, the enzyme 11β-hydroxysteroid dehydrogenase type 1 converts inactive cortisol to its active form at higher rates in abdominal fat tissue than in lean men, even though overall cortisol production in the body is similar between the two groups.

In lean men, insulin reduces the activity of an enzyme in fat tissue that regulates cortisol, but this reduction does not occur in obese men, suggesting a difference in how insulin affects cortisol processing in fat tissue between these groups.

In women who have fat stored around their internal organs (visceral obesity), the fat tissue produces more of a specific enzyme and hormone related to stress compared to women without this type of fat buildup.

When obese men lose weight by dieting, their body doesn’t make less cortisol overall—but because they still have some fat left, the cortisol they do have is now more concentrated relative to that fat, which might trick their body into putting fat back on, especially around the belly.

In women, higher levels of a specific enzyme (11β-HSD1) in fat tissue are linked to having more body fat, especially around the belly.