Is it true people who lose weight have a much lower metabolism

Tezzzz2020

I read somewhere that weight loss causes our metabolic rate to slow down so much so that it is a factor for why people regain the weight they lose. Is this true?

claireychn074

Larger people will have a higher TDEE rate than smaller people I.e. carrying more weight uses more calories. So if you need 3000 calories a day at your max weight, you will need less calories to fuel your daily activities at your lowest weight. (I’m not actually explaining this very well!)

In a nutshell if you’ve lost weight but start to eat too many calories you will gain weight again. Your metabolism hasn’t slowed, but you just need less energy to get around.

Somebody else please explain what I’m trying to say better 🤣🤣

yirara

No, that is not true. If this was true then people who die of lack of food would be overweight, and not skin and bones. It's totally rubbish.

What is true is that your body needs less energy when it's smaller. This starts with your heart having to do less work to pump your blood around, your other organs needing less energy to tend to a larger body, but also includes the energy that is needed to move your body around. Think walking. Say you have a tiny shopping bag. It's easy, you can carry it for a very long time. Now imagine a huuuuuge garbage bag for of heavy things: you can't carry it around quite so long. it's more tiresome, it requires more energy. It's the same with your body.

What's also true is that many people want to lose weight as quickly as possible. Do a crash diet, then go back to their old ways. Meaning they eat as they did before. As I wrote above, a smaller body needs less energy. Eating as before will lead to weight regain because the body doesn't need that much energy anymore. Not convinced? Use for example this calculator: https://www.sailrabbit.com/bmr/ put in your age, gender, size and current weight. See the result to maintain weight. Then do the same but make your weight 50lbs lighter. Then the same but 50lbs heavier than your weight.

Thus weight loss is also the moment to learn about how to eat properly, and how much to eat as maintenance will come sooner or later. At that point you need to know how much to eat to maintain your weight and not to regain it. It also means that you should chose a way of eating that you want to keep up after weightloss as you'd otherwise need to figure it out all again. Losing weight with keto, but going back to old way of eating? Sure, can go well, but might also go wrong.

cmriverside

There is a bit of metabolic adaptation, so you do have to factor that in at the end of weight loss - BUT - it's not a permanent down-regulation (other than what the first two posts in this thread have already explained.) When I went to Maintenance calories, I knew exactly how much I'd been eating and it should have been a relatively easy transition but dang. I was hungry when I raised calories. I had to kind of watch myself pretty closely to stay at that weight right after the loss of 80 pounds. Hungry...so if I had not known my calorie level and if I had just allowed myself to eat ad libitum, I definitely would have gained. It was uncomfortable for me for nearly a year.

Here's a doctor's explanation (thread) about Metabolic Adaptation/Adaptive Thermogenesis (sometimes called starvation mode, incorrectly)
https://community.myfitnesspal.com/en/discussion/1077746/starvation-mode-adaptive-thermogenesis-and-weight-loss/p1

..And this really helpful tool to use to sort of hack the process. Down-regulated calorie needs do bounce back to higher, more normal levels after eating normally for a while post-weight loss. A refeed can help if you do this along the way during a significant weight loss program:
https://community.myfitnesspal.com/en/discussion/10604863/of-refeeds-and-diet-breaks/p1

Tezzzz2020

Thank you everyone for responding and clarifying this. I was a bit confused and have been trying to understand why I cant maintain my weight loss and read somewhere that metabolism becoming chronically low was a possible factor.

@cmriverside thank you for sharing these articles, I will have a read through and try to break the yoyo weight loss cycle. Also, I need to reframe my mindset and accept that weight loss is half the battle, and that maintenance is the second half, that takes conscious effort and time.

cmriverside

You're welcome, you might also want to go to the subforum "Maintaining weight" and read in there...especially the "Most Helpful Posts" section.

Forum: https://community.myfitnesspal.com/en/categories/goal-maintaining-weight

Most Helpful posts: https://community.myfitnesspal.com/en/discussion/10300324/most-helpful-posts-goal-maintaining-weight-must-reads#latest

PAV8888

@cmriverside 👍

I figure from a few months to one to two years after major weight loss for things to settle towards a normal. And it depends on how long and how large a deficit, frequency of refeeds, degree of leanness, and... the individual

Some adaptation plus hormonally driven increased hunger post loss? Enough research showing hints to say: Sure!

Enough to guarantee failure? Not so.

Enough for us to respect the immediate aftermath of weight loss and plan for it? You better believe it!

luisanapa

A 'normal' but reduced calorie intake will not have much, if any, effect on metabolism, but SEVERE calorie restriction CAN lower metabolism and it can cause other problems, including fatigue and eventually weakened bones. Depending on your build, age, etc., it's recommended you not go below 1200-ish per day.
https://www.healthline.com/nutrition/calorie-restriction-risks
Having said that, one day of missing meals won't affect your body (unless you have some underlying health problem). Note that fasting for rapid weight loss should only be done under medical supervision and typically movement is minimal during the fasting period. If you're interested in going that route, there's a fabulous (and surprisingly affordable) clinic: True North Health Clinic in Santa Rosa CA that has supervised water or juice fasting programs and/or vegan diets + food/nutrition education. [I'm not affiliated w/ them, but went for a week about 10 yrs ago and thought it was great.]
https://www.healthpromoting.com/
Good luck!

AnnPT77

Tezzzz2020 wrote: »

Thank you everyone for responding and clarifying this. I was a bit confused and have been trying to understand why I cant maintain my weight loss and read somewhere that metabolism becoming chronically low was a possible factor.

@cmriverside thank you for sharing these articles, I will have a read through and try to break the yoyo weight loss cycle. Also, I need to reframe my mindset and accept that weight loss is half the battle, and that maintenance is the second half, that takes conscious effort and time.

I won't say this applies to you, but from my own past experience, and watching people around me pursue weight loss, there are a few things that are common patterns that IMO can make regain more likely:

1. Treating weight loss as a project with an end date, after which things "go back to normal". IMO, for anyone who's been overweight for some time, weight management is a long term, maybe permanent, part of life.

2. *Not* experimenting, finding and firmly grooving in - at least toward the end of weight loss - the *habits* it will take to happily stay at a healthy weight long term (this is related to #1, but not identical). IMO it's ideal to accomplish this "new habits" thing before the end of loss, so that going to maintenance is a simple matter of adding a few calories to an easy-to-sustain, nearly automatic daily routine, in order to stabilize body weight. Ideally, the habits established will include how to handle vacations, holidays, parties, much-loved treats, etc. They will also include finding a reasonably enjoyable exercise/activity routine (which may be minimal actual exercise, if that's what a person handles best, even though exercise is a boon for health).

3. Desperately pursuing maximum, very fast weight loss all along the way. I think implications of the adaptive thermogenesis & diet breaks threads are that pushing maximum willpower and fast loss all the way to the end is that any adaptive thermogenesis that occurs will be more extreme; that hormonal hunger/appetite snap-back may be exaggerated; that possibly unnecessarily much muscle loss will have occurred alongside fatigue related reduction of daily life activity becoming habitual, so that moving more in daily life is harder, less fun, and less likely, thus decreasing TDEE. Very aggressive loss also makes it more probable IMO that item #2 will not have been accomplished along the way.

I think that if you lose at a sensibly moderate weight, focus on finding new sustainable habits, maintenance success becomes more achievable. Just my opinion, though - from year 5+ maintaining a healthy weight after previous decades of obesity. Riverside's been at it even longer, though.