T Nation

Bodyfat % Men vs Women


Not sure where to post this, and I haven’t found an answer on this or any other site.

A group of friends, all work out. mix of adult men and women. want to have a contest to lose 5% body fat. want to be fair when deciding a winner.

the question then is would a woman have to work harder to lose 5% body fat than a man would.

men usually have more muscle mass than women, so they can burn more calories just based on that.

i also know that one pound of fat is the same number of calories for a man and a woman. and the same caloric deficit is required man or woman to lose one pound.

my thought is that it would be harder for a woman to lose 5% bodyfat

if that is true, are there any studies/data that state (for example) that if a woman loses 3% body fat, that is equivalent to the work required for a man to lose 5% ?


Do you mean 5% body weight? So a 200 lb man would need to lose 10 lbs while a 150 lb women would need to lose 7.5 lbs to each lose 5% BW.
If you mean lose 5% body fat, that would be harder to measure. First, you’d need to know your % body fat (let’s say you’re 20% body fat at 200 lbs) to find your total body fat. That would mean you have 40 lbs of body fat. To lose 5% body fat means you would lose 2 lbs of your 40 lbs of body fat, bringing you down to 38 lbs body weight. Of course, you can’t do this only on the scale because you’re losing water/muscle, etc… and not just fat as you lose weight.
So, I think you should keep the contest to losing a percent of someone’s body weight rather than a percent of their body fat.


thanks for the reply, and i agree, we are probably making this too hard— and with too much math.

the thinking was- using your example

200 lbs man x 20 % body fat is 40lbs of fat

goal is to get to 15% body fat, and to do that, would need to keep measuring lean body mass. would hope that as participants are working out, their muscle mass would increase- as would their body composition

using the same example, the 200 lbs man could weigh the same but be at 15% body fat, and would have lost 10lbs of fat. vs when he was at 20%

my question-- and i apologize for not asking it correctly— is it harder for a woman to change her body fat percent than a man, and if so, is there a conversion table that i can use?

for example a 5% change for a man is equivalent to a 3% change for woman.

like you said, probably just easier to see who can lose the most weight.


You’re right in that an athletic woman will have a higher percent body fat than an athletic man. Also, it sounds like your challenge is “who can drop 5 percentage points off their percent body fat”. That type of challenge will mean the higher in fat you are at the beginning, the easier it will be. Someone at 13% body fat will have a harder time dropping to 8% compared to someone who’s 25% body fat dropping to 20% (even though the latter will actually have to lose more weight and fat overall).


My parents are both on weight watchers, and from the recommended calorie restrictions it does appear that a woman has to eat fewer calories to lose the same amount of weight. However, given the tendency towards yo-yo dieting and its negative effects upon health, I would suggest ending the competition and just encourage everyone to eat right and exercise as a daily habit and let nature take its course.

It wouldn’t surprise me if women’s different reproductive role has led to their bodies evolving to hold onto more surplus energy than men’s bodies do, which is ironic considering the greater social pressure on women to be thin. I’ve been able to get away with “love handles” as long as my chest and shoulders overshadowed them.


If you do percent bodyweight I’m not sure this matters for a competition. Look at the TV show biggest loser they just did it as a percentage of bodyweight and men didn’t really seem to have a huge advantage over women who still won the show often. Womens may have a higher body fat when they are lean compared to men but that also means they have a higher body fat when “fat” compared to men, so they start higher and end higher but the % lost is the same for competition purposes.