When you embark on a weight loss journey, it’s expected that, at some point, you will plateau. This is because, as you lose weight, you burn fewer calories moving your body around. At some point, your energy usage becomes low enough that it is equal to your energy intake. Your calorie deficit is wiped out, and you stop losing weight.
At this point, conventional wisdom suggests that you just need to do more exercise to re-establish a calorie deficit, and you’ll once again start to lose weight. But research suggests that this may be a fruitless strategy or at least one that provides diminishing returns. That’s because the human body compensates for increased energy usage during exercise by reducing energy expenditure on other bodily processes. So, the net impact of your increased exercise efforts may be much smaller than you think.
In this post, we take a brief look at this phenomenon of energy compensation and explore strategies to minimise its impact.
What is energy compensation?
From an evolutionary perspective, energy compensation makes sense. When food is scarce, and energy is a precious commodity, it makes sense to conserve energy as much as possible. If you expend a lot of energy gathering your food, you’ll do better by diverting energy away from other biological processes so that you don’t run out of energy.
In the modern world, where so many people are trying to lose weight, energy compensation is a hindrance. Ideally, you’d like to add to your basal energy burn all the calories you burn on exercise. Instead, your basal energy burn is reduced to compensate for the energy burned during exercise. How frustrating!
Recent research suggests that energy compensation averages 28%. In other words, only 72% of the energy you burn on exercise contributes to your overall daily energy burn. The study also shows that, while there is no real difference between men and women or between young and old, there is a lot of variation between individuals. You may be a strong energy compensator or a weak compensator. This may explain why some people have more trouble losing weight than others.
Energy compensation can be considerable, adding up to many hundreds of calories. This is especially true the longer the weight loss journey and the further you get from your original weight. That’s bad news for anyone on a long journey. That means that you may already be experiencing a lot of energy compensation at the point where you plateau and efforts to increase exercise may be fruitless.
What causes energy compensation?
Right now, there isn’t sufficient evidence that supports one theory over another. But several suggestions have been made
Reductions in basal energy expenditure
This is a fancy way of saying that it may be due to reductions in energy usage on other fundamental biological processes. These might include immune function, reproduction, repair and protein use, for example.
Hormonal changes also likely contribute to basal energy expenditure. For example, reductions in thyroid output will slow your heart rate, lower blood pressure and reduce energy consumption. You’ll feel sluggish and lacking in energy, so you’re likely to move less and burn fewer calories.
But probably the most likely mechanism of reduced basal energy expenditure is improved mitochondrial efficiency. What does this mean? It means the body becomes more efficient at generating ATP from oxygen. This happens at a fundamental level within the mitochondria of cells.
One of the mechanisms by which mitochondria become more efficient is by improving fat oxidation. Using fat for fuel in preference to carbohydrates results in a larger number of ATP molecules being produced per atom of oxygen. That means oxygen usage and energy consumption can be reduced.
Reduced proton leakage
Another mechanism is to reduce ‘leakage’. When mitochondria are inefficient, some oxygen is used without generating ATP. Instead, it is wasted in the form of heat. This is referred to as proton leakage. When the mitochondria become more efficient, leakage is reduced, which, in turn, reduces metabolic rate. If you’ve ever been in an extended calorie deficit, you may have noticed that you get cold more readily.
These changes are promoted by exercise and weight loss. Exercise is excellent at improving fat oxidation and mitochondrial efficiency.
Studies show that if weight remains stable, there is no reduction in basal energy usage. It’s the calorie deficit and resulting weight reduction that gives rise to a change in basal energy burn. And the larger the calorie deficit and the further you get from your original weight, the greater the changes in basal energy usage.
Reductions in NEAT
NEAT stands for non-exercise activity thermogenesis. That basically means the energy you burn doing other stuff other than exercise. That might include pottering around, fidgeting, maintaining posture, sitting and standing.
There is a little evidence that NEAT is reduced, particularly with long-distance or ultra-endurance athletes. But essentially, the evidence is lacking that NEAT is a significant contributor to energy compensation.
These findings may be due to study design. I can tell you from experience that NEAT is reduced under extreme circumstances. Every time I prepare for a physique competition and get my body fat levels down to 7% or less, the reduction in NEAT is very evident. I lean against walls, sit down at every opportunity, think less clearly, articulate less energetically and fall asleep where it might seem impossibly uncomfortable. It’s clear my body is trying to conserve energy.
The changes in NEAT may only be slight and not even evident initially. But after a prolonged and large calorie deficit and significant weight loss, I’m sure they will contribute more to overall energy compensation.
Exercise and energy compensation
A prolonged exercise programme and its associated weight loss will increase energy compensation. Research suggests that higher intensity training can have a reverse effect on energy compensation. For example, high-intensity interval training (HIIT) creates excess post-exercise oxygen consumption (EPOC), or afterburn, that can keep the metabolism elevated for hours after exercise. HIIT has also been associated with increased NEAT and reduced appetite. Those effects are not seen with steady aerobic exercise.
Resistance training, like HIIT, is also a potent mobiliser of fat reserves. But it has the benefit of maintaining muscle, which helps to preserve basal metabolic rate. If done in the right way, resistance training is a form of HIIT, with all the benefits of HIIT in terms of energy compensation, but with the added benefit of muscle maintenance.
So, what would be our recommendation? Perhaps you’re thinking that a mixture of resistance training and HIIT would be a great way to combat energy compensation. In my experience, that’s too much for the body to cope with, especially if you’re in calorie deficit. Both HIIT and resistance training induce central fatigue or nervous system fatigue. Your nervous system needs rest and recovery.
So, for this reason, I recommend a mixture of HIIT-style resistance training mixed with aerobic exercise. Despite the association with energy compensation, there’s still a place for cardio. But I’d suggest you do it in the morning when your metabolism is restored by sleep, that you take a caffeine shot beforehand and that you eat as soon as you are hungry afterwards. Do that a few times a week and mix it with resistance training a few times a week. Make the resistance training hard, heavy and intense so that it has significant EPOC and muscle-sparing effects.
Eat more, not less
Let’s say you get stuck on your weight loss journey. You’re worried that more exercise will be fruitless because it will leave you exhausted and increase energy compensation. Instead, you think, why not cut some more calories from your diet?
Don’t do this! Cutting calories further is simply another way of increasing your calorie deficit, making it likely you’ll still increase your energy compensation. Instead, try increasing your calorie intake. It sounds counter-intuitive. But remember, your body has had months of calorie shortage and has found ways to preserve energy. By feeding it some more energy, you allow these energy preservation mechanisms to unwind.
There isn’t much research on this specific topic, but I have four good examples of where more food, not less food, was the solution to continued weight loss.
If you’ve had anything to do with bodybuilding, you’ll know about the concept of a refeed. This is a brief overconsumption of calories to ‘re-stoke’ the metabolism. It’s very common to plateau when you’re aiming for sub-10% body fat. Refeeds are an important part of keeping the weight loss going, restoring hormone balance and keeping you sane!
We signed a client a couple of years ago who was carrying a lot of body fat and had low muscle mass. He had been eating about 500 calories a day for many years. His weight was stable, and he was unable to lose any more weight.
The first thing we did was give him a ‘normal’ number of calories. Lo and behold, he started losing weight again. We kept his calorie deficit moderate throughout, and he lost a further 20 kg. We had taken away his energy and nutrient crisis so that his body could function normally and respond to standard weight loss best practices.
This client is still with us, and we are now emphasising muscle gain in his programme.
I recently helped investigate another weight loss plateau. The client was getting downhearted, and her energy levels were depleted. At one of her check-ins, she casually mentioned she had been skipping meals to continue losing weight. Of course, this hadn’t worked. Instead, her hormones had been affected, her NEAT reduced, and her energy levels had taken a dive. We asked her to eat all her meals and snacks but made some other more minor changes to spark a return to weight loss.
Of course, like many weight loss clients, she could have exercised more. Her exercise regime was two personal training sessions and some morning walks. I feel there was more in the tank there, and she had not reached the ‘optimal’ levels of exercise.
After losing five stones, one of our clients plateaued. And despite making several changes, he remained stuck. He reported calorie intakes of around 2000 calories per day and, according to his activity tracker, energy usage of well over 3000 calories per day. Why was he not losing weight? Almost certainly because of energy compensation. And quite likely, he was a strong compensator.
We gave him a refeed! We asked the client to consume double his usual amount of carbohydrate, just for one day. This sparked a further 3.5 kg weight loss.
Increasing rather than decreasing calories makes sense from the point of view of competition for energy. By refeeding, we temporarily halt the calorie deficit, restock energy reserves and remove the need for the body’s cells to compete for limited energy supplies. Client 3 reported that his refeed made him heat up. That was presumably the resumption of ‘leakage’, producing heat.
Note that the client wasn’t doing any cardio as such. He was initially walking a lot but had reduced his walking before plateauing. At no point had he joined a gym and attempted cardio or additional resistance training over and above the single personal training session he had at our studio in Northampton. I have no doubt that additional exercise along the lines of our recommendation would have sparked further weight loss, even though he was likely a strong compensator.
Some research suggests that a sustained exercise habit can overcome the downsides of energy compensation.
Energy compensation is the reduction in non-exercise energy usage to compensate for energy burned during exercise. It’s a frustrating physiological by-product of evolution that hampers those trying to lose a lot of weight.
But there are things you can do to minimise its effects. Here are our recommendations:
- Keep the calorie deficit moderate, around 500 per day ideally, but no more than 1000 calories.
- Do everything you can to preserve muscle tissue
- Prioritise protein: get several intakes of high-quality protein per day.
- Choose a mixture of cardio and intense resistance training also to preserve metabolism.
- If you slow down or get stuck, try reducing your calorie deficit instead of increasing it by eating less or exercising more. Try eating more carbohydrate.
- Increase your levels of exercise until they are ‘optimal’. This is where you feel that your exercise efforts are having a good effect. If you think your exercise is not producing any additional weight loss benefit, then you’ve gone past that optimal level.
Your body is going to defend high body fat levels more and more as you lose weight. And you may be a strong compensator and genetically predisposed to weight gain. But that doesn’t mean you can’t lose weight and you shouldn’t try. It doesn’t mean that the defence of body fat reserves can’t be beaten. Be resilient, be patient and keep trying.