Hacker News Reader

Comment by ChemicalWarfare | Hacker News Reader

Anecdotal evidence from being a gym rat for 20 years, although I'm sure there are studies out there to prove this. Maybe :)

No doubt that diet+exercise is the way to go when it comes to long-term weight management. The thing is, "weight loss" in and of itself is a misleading metric. You're losing weight! Great! But hold on a minute - your gut is the same size but your biceps is smaller and your strength is way down. What happened? You lost weight alright but its muscle you're losing, not fat.

So where I'm going with this is exercise is very important to make sure you don't negatively impact your body composition by losing muscle weight when dieting.

View on HN

Muscle requires a lot of energy to maintain, so when your calories drop your body starts shedding it to be more efficient so long as you are also inactive.

If you stay active you will lose strength on a calorie deficit but you will not lose muscle mass. That's why you can do a cut, and your lifts will go down but you still look great at the lower body fat. The muscle mass is still there.

http://fitnessblackbook.com/main/starvation-mode-why-you-pro...

Trained individual on a reasonable diet, taking an intelligent approach to cutting will lose 'some' strength and 'some' muscle when cutting body fat, yes.

Someone who is out of shape might actually be able to gain both muscle and strength while losing weight when starting out as long as they are lifting in addition to cleaning up their diet/reducing calories. The less fit they are the better the gains, which I guess is borderline captn obvious territory :)

I wouldn't say it's captain obvious territory. I don't think most people realize how fast muscle development drops off after a year of serious training.

> If you stay active you will lose strength on a calorie deficit but you will not lose muscle mass.

That's not true. If you're on a calorie deficit you will lose muscle mass. You'll lose less if you exercise.

Exactly - percent bodyfat is a much better target metric than weight.

Agreed. The problem is that weighing yourself is easy, but measuring body fat is way harder. Most of the at-home measurement tools are wildly inaccurate; the accurate ones are either expensive or inconvenient.

I don't trust the absolute numbers, but the data from my FitBit Aria has a pretty low variance over time:

http://imgur.com/5AgKU9F

It does seem to be tracking reasonably well - I've lost a bit of fat, but not a significant amount since then. Given what I see in the mirror, I think 16-17% is about right. There are some weird fluctuations, but we're talking 1-2% day to day. The range of the graph is about 4-5%.

The trick is to measure several times a day if you get the chance (or at the very least when you get up and when you go to bed) to smooth out any fluctuations.

The gut-to-hip ratio is a rough, but effective, alternative. At least if you start from an overweight/obese body type.

I don't know if the article says this but you don't have to "exercise" per se but you should be "active" even if it's just walking.

Reply on news.ycombinator.com