[TheOtherHobbes]

4. will (literally) kill you because your metabolism slows down as you age and you have to choose between obesity and eating much, much less. Exercise helps but will only get you so far.

In my 20s I would eat ~1000 calorie meals with an entire pizza, salad, rich dressing, and a big slab of chocolate fudge cake. I was never slim, but I wasn't obese either.

If I tried that today I'd be breaking the scales in a few months.

Having to cut down on food a lot has been one of the hardest adjustments to make. Quite a few of my friends have never managed it and they're now dangerously beyond a reasonable weight.

[JackMorgan]

As someone who's over 35 and has dropped from obese to normal BMI, I can say it's absolutely possible to keep the metabolism running fast. However, at least for me, it's quite difficult and always has been.

Very quickly I'll go from eating a huge number of calories in a bulk phase, start cutting, and watch as over ~10-12 weeks as I need fewer calories each week to achieve a steady fat loss. After about 12 weeks of cutting fat I've gone from needing X calories to lose a pound a week, down to needing only 0.5X. At this point, I'm eating very few total calories. So I stop, and spend another 10-12 weeks slowly adding calories back in along with vigorous exercise until I'm gaining a steady half pound a week (maybe 50/50 fat/muscle). I'll rise up in weight about half of what was lost in the cutting phase, but ideally only about 1/4 of the fat lost. Once my total calories is back to a very high starting point, I'll start the cut again. This is the "secret weapon". I've lost a huge amount of body fat since starting this program, and my shoulders and legs are starting to stretch seams.

I came to this program after ~10 years of trial and error, but it works wonders.

If you need a starting point, Renaissance Periodization has some very expensive templates that can help a person get started with this. Or, just buy a scale, measure and weigh everything, and start cycling cut and bulk cycles every 10 weeks or so. Always aim for a pound lost a week, continuously dropping calories to maintain that rate, then bulk for 10 weeks, aiming to gain 0.5 pound a week along with strength training, adding calories each week to achieve that goal. Also, when cutting, long slow calorie burning like rucking, hiking, cycling, or swimming is perfect to help keep the daily calorie levels high. If not for those, I'd find my total daily intake to be unpleasantly low.

[moltar]

The answer is fasting. That’s the missing feature of our modern life. Humans need to fast to clear out the glycogen stores and liver fat.

[KozmoNau7]

I would love to see the research backing this, because that would be a quite simple lifestyle change for most people.

However, it does also have an air of "this one trick will solve obesity!", which should be viewed with skepticism.

[DougWebb]

I think most people would disagree with your definition of "quite simple".

Going from three meals a day to a 16:8 eating pattern (16 hrs fasting, 8 hrs eating window) isn't too bad. It's basically skipping breakfast. Shortening the eating window until you're eating one meal a day is tougher. Then extending the fasting period > 24 hrs is tougher still. You can't just jump into this stuff while you're carb-addicted and your body is screaming for glucose. Getting used to a keto-style diet, even if your carb intake is just low but not keto-low, helps a lot.

[KozmoNau7]

If you're a somewhat lazy young person like I was, falling into a one-meal daily routine could just happen due to a busy daily schedule. Unfortunately I also managed to put on weight during that time, so my meals of choice were probably non-optimal and probably too large.

I stand by that most people should be able to do it, as long as they can get over the hangry phase.

[moltar]

I’m sorry, I’m too lazy to find the studies. But there are lots. I’m not saying anything fringe or controversial here.

Check out these two things that come to mind, both cite an extensive list of studies:

- https://youtu.be/dBnniua6-oM

- https://youtu.be/tIuj-oMN-Fk

[voisin]

There are hundreds of links on HN about fasting. You cannot lose fat without first depleting glycogen stores. You can exercise these stores away and then in the absence of further caloric input your body turns to fat stores. Or if you fast, the absence of caloric input means your body will naturally burn its glycogen stores (takes longer if you aren’t exercising, for obvious reasons).

[nefasti]

Nope. Your metabolism is related to your current weight, unless you have some specific diseases. You probably don’t remember your actual activity level from the past.

https://www.liebertpub.com/doi/full/10.1089/met.2016.0108