I think you are confusing calorie restriction with fasting.
You can be regularly fasting AND eating the same amount of calories on average. You just eat more between fasts. Fasting just means there is enough period between your meals for your body to get stressed a bit and to have to go into fasting mode.
The idea here is that the act of fasting alone promotes positive changes. A side effect is that most people, usually, are not able to make up all of the calories in a short time. Meaning if you eat only every other day, it actually is quite hard to eat two days of calories within one day.
For me fasting is much more bearable than "dieting". For me dieting just means I am hungry constantly while fasting means I just need to survive until the next meal when I will be able to eat as much as I want and feel satisfied.
Also fasting is sort of self-regulating. As long as I can keep to the fasting period and I am not criminally overeating outside of it, I can reap the benefits of weight loss as if I was on caloric restriction but without having to think about it or counting calories.
Neither caloric restriction nor fasting necessarily means wasting of your muscles. Though if you fast long enough or restrict your calories enough at some point it will become unavoidable.
I personally think it all depends on your cost/benefit. Fasting brings positive effects you can't emulate in any other way. But you don't need to be fasting constantly, I personally think you can get a lot of effects by fasting occasionally (like one day a week, for example).
And without getting too much into details, I think if you are absolutely unwilling to do fasting and would prefer caloric restriction there still are better ways to do it. It is better to reduce your calorie ingestion by reducing hunger relative to your output.
For example, jogging every day in the morning, eating whole fresh fruit and vegetables some time before your meals, will have effect of reducing your hunger and making you eat less without having to be constantly hungry.
But the parent wrote "Does such caloric restricted diet allow one to maintain muscles and/or strength?" Which means he is asking about caloric restriction responding to comment about fasting.
I'd say the parent's question is perfectly valid: “He gets by on one meal a day of 1500 calories.” implies, in fact outright states, a calorie restricted diet as well as a temporally restricted one.
Most people would struggle to finish a meal with half those calories, and rightly so - it's excessive. Strongmen could go over that amount a day when bulking, maybe, and that's about the semi-practical limits of the human body (while maintaining at least some semblance of health).
If your body fat percentage is high enough (25% or more for example) it is even possible to gain muscle on a calorie deficit. Many studies have shown it's possible to lose fat while gaining muscle for such individuals.
I'm not sure about the "one meal per day" part though - not sure if there are studies for that combined with a calorie deficit.
The lower your body fat percentage is, the harder it is to diet without losing muscle.
Given the goal is lifespan extension, the implication seems to be the person is trying to do this for an entire lifetime. You can't eat at a calorie deficit in the long term without starving at some point, so that means 1500 KCal at some point has to be equal to your TDEE. There is no way to get that low permanently while having any meaningful amount of muscle.
The comment below claiming TDEE of 1900 for a 190 lb "active" male is interesting. I currently use the Macro Factor App to track meals and TDEE, make everything from scratch from raw ingredients, weigh and measure absolutely everything, including any cooking oil, so the estimates are good as you can get without checking into a metabolic ward, and I'm a 41 year-old male who currently weights 187 lbs and my TDEE is roughly 2900. That's at an activity level of lifting for 60-90 minutes 6 days a week, walking usually one to three hours a day at a pretty leisurely pace, usually while listening to a podcast or playing Pokemon Go, and I live in a four-story house so walk up and down stairs quite a bit.
The famous study on Amish body composition and activity levels had them at an average of 18000 steps and 9% body fat, and they were eating ungodly amounts of food, pounds of potato and grain, upwards of 4000 KCal a day in most cases. I suspect what a western white collar worker considers "active" is skewed a bit. I doubt there were many pre-industrial adults outside of nobility who got by on 1500 a day. Maybe some had no choice during a very harsh winter, but not as an everyday thing for years.
> If your body fat percentage is high enough (25% or more for example) it is even possible to gain muscle on a calorie deficit. Many studies have shown it's possible to lose fat while gaining muscle for such individuals.
Being a vegan it is very difficult to get enough protein needed to maintain the existing muscle mass, not to mention grow muscles at 1500 calories per day. That's below base for most men even with a lifestyle that does not include anything other than NEAT.
All the energy needed for non-exercise activity i.e. eating (edit: muscle movement needed to eat such as lifting a spoon, not the process of digesting), scratching your head, typing on a keyboard, yawning, etc
"One meal per day" probably won't cut it. I think the idea here is that:
1. you have to do resistance training (lifting weights)
2. you need to consume enough protein so that it can be used to build the muscle mass (100-150g per day)
3. you limit calorie intake by skipping carbohydrates and fats - this is what your body fat can easily replace.
You probably cannot limit yourself to just one meal per day, or skipping eating some days - your body being in the "fasting mode" is the opposite of "muscle building mode".
another problem here is: high fat percentage lowers the testosterone levels, which is not great for gaining muscle. Some testosterone-boosting supplements, like zinc might be useful here.
Sounds about right. Regarding point 3, 1500 kcal per day leaves more than enough budget to have some fats and carbs - 150g of protein is only 600 kcal.
> high fat percentage lowers the testosterone levels, which is not great for gaining muscle.
Anecdotally speaking, I was able to gain muscle / increase strength just fine when I started dieting, and I was definitely above 30% fat. Even if this isn't the case, the fat should melt away quickly on a good diet, so it probably isn't a big deal in the grand scheme of things.
For what it's worth, are you sure you were gaining muscle and not just gaining strength? There are many possible strength-gaining adaptations that can happen in an individual who is gaining no muscle. Actually gaining lean body mass while losing weight is very unlikely. It requires a very untrained, overweight individual with a relatively modest caloric deficit.
> It requires a very untrained, overweight individual with a relatively modest caloric deficit.
It's hard to say because many overweight people already have a significant muscle mass, just those muscles are underused and hidden under the fat. When one starts to exercise and looses some weight their muscles' volume will increase with a better blood flow, and will get the proper shape and also become more prominent with less fat over them, but they'll probably not actually increase the muscle mass itself - it's just that we're now able to see them better.
I can't prove that I was gaining muscle, but it sure looked like I was. It's not particularly rare either, there are many sources out there debunking the idea that gaining muscle requires gaining weight. This video cites some:
Even if I had only been gaining strength, that's still a good thing. So in practice this doesn't change the fact that it's a good idea to train while dieting.
Muscle gaining requires quite a bit of protein. It is not very difficult to constantly get enough protein in a non-vegan diet while consuming only 1500 calories even on OMAD. It is far more difficult to accomplish with a vegan diet on OMAD or IF cycle while only consuming 1500 calories.
It’s not so hard with protein powder. My powder would give me 100g protein in 440 calories.
That leaves just over 1000 calories to eat nutrient dense foods like broccoli and foods that bring even more protein.
(Just for fun, 1000cal of kale/broccoli aka 3kg fills all nutrient bars in cronometer except b12 and d3 and it has 70-90g protein)
Though i’m also not very convinced that we need nearly as much protein as broscientists think. If you aren’t jacked and you can’t grow on 100g protein per day at 200lbs, you aren’t covering enough of your max effort at the gym. Most people make that mistake and do grow no matter how much protein their ingest.
People with low muscle mass definitely don't need 440 calories of protein shake a day to gain muscle.
I was getting great results with about 110 calories worth 30 minutes after exercising (25-30g? "1 scoop" at any rate) plus creatine. I simultaneously lost a lot of fat according to the fat percentage scale at the supplement store.
Anecdata here but a few months ago I started eating "one meal every other day" (a massive ribeye with butter and eggs. i have no idea what the calories or protein or whatever are.). I had been strength training for a while without dietary control.
I'm severely obese. Significantly less so than I was when I started fasting, but still over 35 BMI.
I think I've gained a small amount of muscle? It's definitely slowed down since before I was fasting, but lifts are progressing still. It may just be skill progression but these are simple lifts that I'm pretty familiar with (overhead press and deadlift), and I feel like I'm still gaining real strength.
I don't know how to judge muscle size really, especially since I'm losing body fat which is obviously making them look more pronounced.
I do take one "testosterone-boosting 'supplement'" (the main one). I've been running a test level of around 900.
> I do take one "testosterone-boosting 'supplement'" (the main one). I've been running a test level of around 900.
That's basically a PED for your condition. That + protein + muscle load from lifting means you will be gaining muscle and losing fat as long as you engage in a progressive overload ( which is much easier to do with T boosters ).
You can't cheat the laws of metabolism. If you're in a large caloric deficit, the body will not waste energy building muscle, which is an EXTREMELY expensive process. If you weight train and consume hundreds of grams of protein per day, you can work to maintain the lean tissue, and in some cases if you're a beginner and/or obese, you can put on some muscle in the beginning, but it won't last.
Building muscle requires a slight caloric surplus and sufficient protein intake spread out through the day (last part is more about optimization)
Exactly, like I said, if you're overweight like the cops in the study, or new to training, or you take steroids, you can build muscle and lose fat. But it's not forever, at some point you'll plateau and need to pick a lane: lose fat and maintain LMB, gain some fat and gain muscle.
We're not talking insane caloric surpluses for the latter either.
Muscle burns calories. My base metabolism increased by 100-200 calories (from < 1400) after six months of strength training 3 days a week for 30 minutes. (Computer programmer with very little muscle mass...)
Anyway, if you want to lose weight and maintain muscle mass, add protein shakes + creatine + strength training to whatever calorie restrictions you are doing. Get your body fat percentage tested every few weeks. Adjust calories as appropriate to draw down fat or build up muscle. In steady state, most people can either gain muscle or lose fat, but not both at the same time.
(The above works OK for absolute beginners; it gets harder to improve as you improve.)
The "A Workout Routine" book is ranty but has decent introductory routines and links to decent YouTube videos. You'll also need about $150 worth of exercise bands to get started. (Cheap Amazon ones are dangerous, so go to a reputable brick and mortar store's website to choose a brand.)
Table 2 of the paper in low carb + time restricted weight loss in kg at three month was -5.0 +/- 0.4 while body fat -3.0 +/- 0.5 and muscle -0.5 +/- 0.2.
Perhaps if you're obese and your body can burn enough of its stored fat you could maintain it for a while, but 1500 kcal/day is too low for an active person - for most people it barely covers the BMR needs. In order to stop body from reducing your muscle mass you need to stimulate those muscles a lot, you need to use them hard, so your real caloric needs would be significantly higher. Big problem with such extreme restrictions is that in 6 months body will adapt to low calorie intake (shed the unneeded muscles, slow down metabolism), so if you ever decide to stop the program and go back to the normal dietary regime, you'll be in a big problem how not to get overweight really quickly.
They are opposites. You want to get bigger or maintain muscle mass and simultaneously you want to fast (get smaller) and lose mass. Fasting will definitely cause you to lose mass - some fat and/or muscle.
While working out or lifting will cause you to increase your need for calories and food intake. They are opposing forces. You cannot have it both ways.
Fasting = less mass less food intake.
Lifting/muscle mass = more food intake more mass
Fasting doesn't imply eating less (on a larger time scale). You can, for example, eat the same number of calories all at once or spread out over the day.
You'd be surprised... There's quite a bit of genetic variation.
I can maintain my weight at around 190lbs on ~1900 kCal as an active man. That's measuring absolutely everything religiously with a scale, and assuming all oil into every pan is ingested, etc.
My sister is quite overweight and she can maintain weight easily around 1200 kCal.
If yes, I am mighty interested....