How to prevent a plateau when you are in a caloric deficit?

Question

I'm M, 21, 5'6''. Some months ago, I tried losing weight without any resistance training i.e through dieting alone (by creating a deficit of ~ 1500 calories everyday). My weight was 85Kg and I dropped to 76Kg pretty quick. Then I hit the plateau, my weight didn't change from 75Kg for 3 months.

I read some articles and decided to "refuel" my metabolism by eating near my maintenance for 2 months.

Now, I'm on a cut of ~ 500 calories everyday, while hitting the gym 4/5 times a week.

The progress so far has been promising (I'm at 72 Kg now i.e 25 BMI), I have been losing atleast 0.5 Kg every week (as planned). But I really want to speed up my progress i.e increase my intake to 1000 calories a day. I read that once you touch the 25 BMI mark, you really should not reduce your calories to that extent because it will reduce your metabolism.

But for god's sake, I don't want to hit the plateau again. I have to lose 7.5 Kgs. Is it inevitable that my metabolism will slow down if I go at a deficit of 1000 calories a day? Or is going slow (~500 cals), really the best option?

Answer 1

There are many factors that affect metabolism.

Size - The heavier you are, the more calories you burn existing. Also moving at a heavier weight burns more calories than moving at a lower weight. So as you lose weight you'll burn less. Muscle mass uses more energy than fat mass so ultimately you want to try to retain as much muscle as possible.

Thermic Effect of Food (TEF) - The amount of calories it takes to digest the food you eat. Some foods have a higher TEF than others. Also eating more food will cause the calories burned by TEF to go up, and in the inverse, the TEF will go down when you eat less. There's not much that can be done about that but at the same time it's a very small contributing factor.

Non-exercise activity thermogenesis (NEAT) - The amount of calories you burn doing things that don't involve exercise. This tends to be the biggest factor with plateaus. Your body just subconsciously will stop doing things or do things less energetically to save energy. For example, I personally am a big fidgeter, but when I'm on a diet I will stop fidgeting. I'll eventually start walking slower. I become increasingly lazy and stop doing tasks or do them half-heartedly. Even small things will change like I've heard some people notice on video that their blinking slows down. These small changes when spread throughout a day will really add up.

Exercise activity - The amount of calories you burn doing exercise. Your performance, and thus energy expenditure, will go down as energy goes down.

What does all this mean?

The ultimate goal is to retain as much muscle mass while simultaneously keeping energy expenditure up. The first thing to do would be to go slow. A 1000 calorie a day deficit will surely eat up more muscle mass and cause you to crash faster. A slower, 250 to 500 calorie deficit will be much better.

Another effective strategy to this would be the "diet break". A diet break is basically where you eat at maintenance for a short amount of time. Though instead of two months off, you can do two weeks off. So you could, for example, eat at a 500 calorie deficit a day for two weeks, then eat at maintenance for two weeks. Then diet for two weeks and maintenance for two weeks. This will cause your NEAT and exercise performance to more-or-less stay the same. You may even regain muscle lost during the diet phase while in the maintenance phase. This will effectively double the length of your diet, so it may not be a good strategy if you're trying to make weight for some kind of competition.

You'll inevitably hit a plateau if you diet long enough. In which case, congratulations, you found your new maintenance. At this point, you can either drop calories even more, (shudder) increase cardio, or slowly increase calories. If you slowly increase by adding ~50-100 a week, then your NEAT will slowly but surely go back up. After a couple months you can try dieting again. So if you're eating at 1300 a day on your diet, increase to 1350 a day for a week. Then do 1400 a day for a week, then 1450, 1500, and so on. Once you're eating what you were prior to your diet (maybe slightly less since you would be smaller now), then you can restart.

Answer 2

You can experiment to see what level of deprivation negatively impacts performance for you specifically (everyone is different), but in general it is a good idea to take a more modest approach to fat loss the leaner you get.

Your metabolic rate will decrease as you get smaller. Why? Because your metabolic rate is dictated by metabolic need and a smaller body needs less energy to sustain itself. You can offset this drop in metabolic rate by adding muscle mass which is much more metabolically expensive than fat mass. You can also simply be more active than you were when you started.

Metabolic rate is also influenced by long term calorie balance. Meaning that it will be artificially lowered by staying in a deficit for a few months and it will be artificially increased by staying in a surplus for a few months. The more dramatic the deficit or surplus, the more dramatic that the body’s response will be. Regardless of that, the body will return to “normal” when calories are returned to a proper maintenance range.

Beyond metabolic rate is the presentation of lean mass and performance. You have already recognized the negative effects that dieting too hard can have on performance, a similar effect may be found on your body’s lean mass (which includes muscle). When you have a lot of fat to lose, you can diet more aggressively with less negative effects. When you have very little fat to lose, the body will preferentially break down lean mass to make up for the deficit - you limit this by dieting less aggressively and telling your body that preserving muscle mass is important by using it.

One final thing to bring up is timing. You can lose weight fast or slow, but you’ll eventually reach your goals regardless of the path that you choose (so long as you stick with it). So what’s the rush? There are benefits to going slower, but there are also benefits for going quicker. My advice would be to go neither too fast or too slow, find an acceptable rate of loss that doesn’t negatively impact performance and stick with that. Unless you are obese, you don’t want to be losing more than 1% of your total weight each week. Everyone wants results by yesterday, but you have to be realistic with what is possible and what the consequences of certain paths entail. If what you are doing is working, why change it up? If you want to see if see if you can improve what you are doing (and what you are doing is working), change it marginally and give it some time to see what happens. Only you can find out how you will respond.