Why do women gain weight easier than men

If women don’t gain weight easier than men, it sure seems that they do. Maybe it’s because women’s bodies undergo more careful scrutiny for extra pounds than do men’s. Maybe it seems that way because men’s clothing is cut to be for forgiving of a few extra pounds while women’s clothes grab every little bump and bulge.

Maybe it seems that way because it’s true; women do gain weight easier than men.


Yes, it’s true. Women do gain weight easier than men. Of course, not every woman gains easier than every man, but overall, females fatten up with less effort. Isn’t that great? It’s easier for us to get fat and we’re judged more harshly when we do.

Here is some of the science behind what makes it easier for women to gain weight. Of course, the study was done with mice, assuming that female mice and female humans have much in common.

In a study, researchers took obese male mice with increased appetite and reduced physical activity and transformed them into lean mice. The same transformation, however was not repeated with the female mice.

Guess which mouse is the female?

Guess which mouse is the female?


Professor Lora Heisler from the Rowett Institute of Nutrition and Health at the University of Aberdeen led the project. According to Professor Heisler, the World Health Organization reports higher rates of obesity in women worldwide, reaching twice the prevalence of men in some parts of the world.

Currently there is no difference in how obesity is treated in men and women. However, what we have discovered is that the part of the brain that has a significant influence on how we use the calories that we eat is wired differently in males and females.

“Cells in this brain region make important brain hormones called pro-opiomelanocortin (POMC) peptides that are responsible for regulating our appetite, physical activity, energy expenditure and body weight. “What we have discovered is that not every POMC neuron performs the same function.”


So maybe one reason women gain weight easier than men is because of our brains. It’s a mental thing. There is definitely a physical reason too. Men’s bodies build muscle with greater ease while women’s bodies tend to bulk up with fat.

The lean to fat ratio is a measurement of the percentage of body fat. The average lean to fat ratio for men is15 to 18% and for women it’s 22 to 25%. The maximum lean to fat ratio for healthy men is 25% and for healthy women it’s 32%.

Having more lean muscle means men’s bodies burn more calories at rest than do women’s. When your female body burns fewer calories at rest, that makes it easy to store excess calories as fat.


There are more hormonal reasons for women to gain weight easier than men.  Women have a hormone called oestrogen. No, if you have never heard of it, oestrogen isn’t a typo. I didn’t mean to write estrogen.

Oestrogen affects a lot of things in women including their moods. It also reduces a woman’s ability to burn energy (e.g. calories) after eating. That causes fat being stored on the female body.

This ability to gain weight easily was a good thing for our female ancestors. It was necessary to survival of the species. Without easy access to food, women’s bodies made efficient use of what food was available to create and nurture new lives.

Hundreds of years have passed since it’s been difficult to find food. In the last 100 years there has been an explosion of highly palatable food available within hand’s reach. Despite the availability of food, our bodies and our brains haven’t evolved much. Our bodies still behave as though they don’t know when they’ll get their next meal.


It makes maintaining a healthy weight a challenge in our modern food-filled environments. Now that you know it’s true, your female body can easily pack on pounds, don’t let it discourage you. It’s possible to maintain a healthy weight by paying attention and monitoring your food and physical activity.


Jackie Conn

About Jackie Conn

Jackie Conn is married and has four grown daughters and four grandchildren. She is a Weight Watchers success story. She's a weight loss expert with 25 years of experience guiding women and men to their weight-related goals. Her articles on weight management have been published in health, family and women's magazines. She has been a regular guest on Channel 5 WABI news, FOX network morning program Good Day Maine and 207 on WCSH.