Why 'Nam Diet' Is More Effective Than for Women

[Asia Economy Reporter Junho Hwang] Why does the same exercise result in a greater reduction of body fat in men compared to women?

A domestic research team has found a clue that may answer this question. Korea University announced on the 25th that a research team led by Professor Minjeong Shin from the Department of Biosystems Medicine at the College of Health Science discovered that the activity of IF1 (ATPase inhibitory factor 1), a type of protein that reflects exercise effects, differs between men and women.

A Protein That Suppresses Appetite in Men

The research team discovered differences in IF1 activity by sex while studying myokines, which are known to break down fat in adipose tissue.

When IF1 was administered to male mice induced to be obese, symptoms of appetite suppression and weight loss appeared. The team explained that when IF1 is introduced into the body, it acts on hypothalamic cells in the brain to activate the appetite suppression center (POMC) and promote energy metabolism, resulting in weight loss. This revealed that IF1 is involved in obesity.

Using big data from Korean genome epidemiology studies, the team also found that polymorphisms in the IF1 gene are associated with obesity-related physical indices in men.

Interestingly, female mice under the same conditions did not show weight loss in response to IF1 administration. Instead, when menopause was induced by ovariectomy, appetite suppression and weight loss effects were observed.

A Clue to Improving Obesity in Modern People

Shin Min-jung, Professor, Department of Biosystems Medicine, College of Health Science, Korea University

Professor Shin stated, "We have found an important clue to explain the differences in exercise effects between men and women, which have not been clearly understood until now," and added, "Based on these results, follow-up studies are expected to greatly contribute to improving obesity and metabolic diseases in modern people."

The research team plans to study why IF1 does not act to suppress appetite in women. They also noted that there may be interactions between IF1, estrogen, and estrogen receptors, and that follow-up research is underway to clarify the exact mechanisms.

This study was conducted under the joint supervision of Professor Hyunsoo Kim from the Department of Anatomy at Korea University College of Medicine, with participation from Harvard Medical School.