Why do women have more fat than men?

Have you ever noticed, especially if you’re a couple, how men can lose more weight on a diet than women can? And more often than not, the amount of weight men lose can be double that of women. Infuriating right? Let’s take a look at the reasons why.

Women are just typically fatter than men. It starts as early as before birth with studies showing that prenatal female babies are in general heavier than their male counterparts.

It’s not fair, but it’s the way it is.

It’s common knowledge that the more calories you eat, the more fat that you store, but this doesn’t paint the whole picture.

One of the key differences is hormones. And after puberty, it gets worse! When women go through puberty, they tend to store more fat in typical female distribution around their legs and bum. Meanwhile, men when they go through puberty, lose a lot of their fat.

Women deal with fat better than men. They are expert storers of fat. Think of the female body as being more effective energy utilisers. They can free more energy to use in the morning, and store it just as fast.

Men also have more lean body mass too, so tissues such as muscle and bone. Lean body mass burns more calories just to maintain, so men will use more calories doing nothing than women will.

The effectiveness of fat storage will fluctuate between women's menstrual cycles too. During the monthly cycle as estrogen decreases and progesterone increases, it’s part of the latter’s job (progesterone) to clear the bloodstream of fats and store them. And this lack of fat in the bloodstream results in cravings for high fat, high carbohydrate foods. I’m thinking chocolate. And all this is in preparation for pregnancy.

And when pregnancy occurs, women gain more fat still, even without eating more, just through hormonal changes. This isn’t happening either through a lower metabolism. In fact, a woman’s metabolism increases during pregnancy. Women just get more and more efficient at storing fat, clearing it from the blood, and into fat cells as the pregnancy continues.

Some part of this efficiency is brought on by bacteria in the gut. As a pregnancy develops, the gut bacteria becomes more and more efficient at extracting nutrients from food.

Women can run on fat as an energy source a lot better than men can. A process called nutrient partitioning governs how we store excess energy. Some will be stored as fat, some as glycogen, and some for immediate energy purposes. Women store more of their excess as fat compared to men.

Women only have to change how efficient they are at storing fat, even by small percentage terms such as 1 or 2%, and that can have a cumulative effect on gaining 1 - 2 lbs of fat per year, even without any changes to their diet.

During exercise, women use fat for fuel more readily than men. This is especially seen in prolonged exercise. But, and it’s huge but (no pun intended), this also creates a spike in hunger levels much more so than men. Women’s post-exercise hunger hormone levels (ghrelin) can be four times higher than a man. So what this means is that you are more likely to compensate by eating more after exercise.

So increased hunger levels is the downside to women burning more fat than men during exercise. But the upside is if you can control the hunger it creates, then you’re more likely to keep it off. It really only becomes an issue if the exercise is vigorous or prolonged. Shorter, less intense exercise sessions don’t result in any hunger spikes. At around 400 calories of exercise energy expenditure, there is little difference between men and women for post-exercise hunger. But even as much as 600 calories exercise sessions the difference in hunger levels is marked.

Another upside to women’s efficiency at storing fat, is that it generally keeps the blood free of lipids therefore lowering their risk of heart problems.

The difference between men and women isn’t only about the amount of fat stored but also the place in which it is stored. Testosterone and estrogen have different effects on where on the body fat storage occurs. When fat binds with testosterone, fat accumulates in and around the tummy area. When estrogen does, you get fat storage around the bum and thighs. This is also influenced by our genes, but ultimately it is our gender which determines where the fat is stored.

All this points to an indelible fact, that women can’t consume the same amount of calories as men. Sometimes men can double what a woman can eat and still stay the same weight. So weight loss for women has to be individual for them, especially portion sizes. Women have to be stricter on the diets than men are. Male bodies are a lot more forgiving than women’s for the odd slip up in their diet. But don’t give up, because if you control your diet relatively well, then exercise will target your fat stores much more efficiently too.