Why do some people lose weight but not body fat?

SSFx19

For example let’s say someone who is 5.2ft currently weigh 65kg and at 29% body fat. This person gets to the goal weight of 55kg but the body fat has only decreased a bit, now only 27%. The person doesn’t look that different after losing the weight.

What’s the reason for this? Is it because this person lost weight too fast?

Luke_rabbit

They lost body fat, just at almost the same rate as lean body mass, so the percentage stayed about the same. If they didn't lose any body fat, the percentage would increase.

It's important to know that it's normal to lose some lean body mass. A smaller body will have less lean body.

MikePTY

That person would likely have a faulty body fat reading. Body fat scales are not reliable. It'd be highly unlikely that someone would lose 15% of their body weight and only actually drop 2% body fat.

When you lose weight, it is usually a combination of fat, water, and lean muscle mass. Obviously you want to try to make it more of the first, and less of the third. Losing weight slowly will help with that. If a person loses too rapidly, they may lose a higher percentage of lean muscle than they would have going slowly. However even that would not be enough to have such little movement in body fat percentage which such a big loss.

cmriverside

How is the body fat being measured?

mmapags

MikePTY wrote: »

That person would likely have a faulty body fat reading. Body fat scales are not reliable. It'd be highly unlikely that someone would lose 15% of their body weight and only actually drop 2% body fat.

When you lose weight, it is usually a combination of fat, water, and lean muscle mass. Obviously you want to try to make it more of the first, and less of the third. Losing weight slowly will help with that. If a person loses too rapidly, they may lose a higher percentage of lean muscle than they would have going slowly. However even that would not be enough to have such little movement in body fat percentage which such a big loss.

This^. My guess is the method of measurement is not accurate. Also, if one is getting adequate resistance training and protein, the amount of lean mass lost can be minimized.

sardelsa

A possibility, which happened to me in the past, I lost muscle. Despite losing very slowly I did not do any resistance training so when I got to goal I looked like a smaller version of my self. Soft and undefined. Not that there is anything wrong with that of course, but I was not happy with it.

Next time around I lifted as I lost and my body composition was so much better when I got to goal. I looked very different despite losing the same amount as before and actually much quicker the second time around.

Danp

10kg loss and only a few % BF change?

I'd suspect that person probably does look quite different as I'm guessing they've probably lost a limb.

Serious answer is that it's probably a combination of poor measurement, lost muscle mass, water retention changes & difference between low/high point natural fluctuation between measurements..

kshama2001

Satomi639 wrote: »

For example let’s say someone who is 5.2ft currently weigh 65kg and at 29% body fat. This person gets to the goal weight of 55kg but the body fat has only decreased a bit, now only 27%. The person doesn’t look that different after losing the weight.

What’s the reason for this? Is it because this person lost weight too fast?

More likely it's due to using an inaccurate way of measuring, such as a bio-impedance scale.

cwolfman13

Satomi639 wrote: »

For example let’s say someone who is 5.2ft currently weigh 65kg and at 29% body fat. This person gets to the goal weight of 55kg but the body fat has only decreased a bit, now only 27%. The person doesn’t look that different after losing the weight.

What’s the reason for this? Is it because this person lost weight too fast?

That doesn't happen. More likely faulty BF% reading from an inaccurate tool like a bioimpedence scale combined with some body dismorphia.

anubis609

Aside from previously mentioned inaccurate body fat measurements, weight loss does not equal fat loss. Yes, fat loss does occur, but lean mass and water loss do too.

It's quite easy to lose *weight* when you restrict calories and minimize protein. Protein breakdown is constant in the body, so without anything to maintain it (via protein intake and adequate resistance training), those numbers on the scale drop quite easily.

To lose mostly fat and reduce the rate of lean mass loss, eat adequate protein and resistance train, while maintaining a deficit. Weight loss may seem slower, but a good majority of that loss will be fat.

cheryldumais

boldknee wrote: »

They lost body fat, just at almost the same rate as lean body mass, so the percentage stayed about the same. If they didn't lose any body fat, the percentage would increase.

It's important to know that it's normal to lose some lean body mass. A smaller body will have less lean body.

I think this and the method of measurement is probably the case unless they lost alot of water due to a Keto diet in which case the water loss is very high. When I did low carb I often lost about 10 lbs of water. Once I started eating carbs again it came back.