When it comes to body shaping, there is no more controversial topic than the concept of energy balance – or EER (Energy Intake, Energy Use). Some argue that “eat less, move more” is the main and only way to regulate weight. Others say this is an oversimplification, hormonal specifics and diets with a ‘metabolic advantage’ are more important.
What is PERE?
It’s a simple way of putting it:
– When you consume more energy than you burn, you gain weight.
– When you consume less energy than you burn, you lose weight.
This is a basic concept in weight management, as close to scientific fact as possible.
So where does so much controversy come from? From the extremes.
At one pole is the group that takes PERE too literally. If you don’t lose weight in any way, the reason is obvious: either you eat too many calories, or you don’t move enough, or both. Eat less and move more.
On the other side are those who think the idea of PERE is flawed (or even a myth). It doesn’t take into account hormonal imbalances, insulin resistance, polycystic ovaries and other health problems that affect metabolism. They often claim that certain diets and foods provide a ‘metabolic advantage’, helping you lose pounds without counting calories.
None of these points of view are completely wrong. Nor is it absolutely correct.
Extremist views won’t do anyone any good – whether you’re a fitness professional or a home dieter – by taking away the chance of seeing the big picture. Let’s break down the most common misconceptions.
PERE is not just about food and exercise
Some people reduce PERE to counting calories obtained from food and spent in exercise and household activities. In reality, the simple form of PERE hides a highly complex (and beautifully worked out by nature) energy balance equation.
The energy balance equation (and therefore PERE) includes all the complex internal processes of the body as well as the external factors that ultimately affect “energy intake” and “energy expenditure”:
These are by no means all of them, but just the basic factors. It should be understood that each one listed can be influenced by: other factors, hormones (leptin, thyroid), sleep, stress, health disorders, taking medication, etc. All of these do not override PERE, but can change the amount of calories we absorb and burn (which determines weight gain or loss).
Calculating calories for PERE is not easy
Many people use calorie calculators to estimate their energy needs and the approximate number of calories eaten. But sometimes they don’t succeed and start to think that something has gone wrong with PERE (or themselves).
The key words here are ‘estimates’ and ‘approximate’. After all, these calculations are not at all as accurate as one would like them to be.
To begin with, the calculations are based on averages, and can give a margin of error of up to 20-30% for young and healthy people. And even more so for people who are older, have various medical conditions or are obese. (So if the calorie calculator readings don’t work for you, just adjust and find your “figure” – the calorie allowance that is close to you – note Zohodnik).
And that’s about ‘energy expenditure’ for now. Things aren’t much better with “intake.” For example, the FDA allows a 20% margin of error in indicating calories on packages, while catering menus can give a 100-300 kcal error in estimating the caloric content of food.
And even if you could accurately weigh and measure every crumb, you still wouldn’t get the exact amount of “incoming energy”. Again different factors come into play here:
We don’t absorb all the calories we eat. The level of absorption varies depending on the type of food. For example, we get more calories from high-fibre foods than is counted, and less than is counted from nuts and seeds.
Each individual’s absorption rate is determined by his or her set of bacteria in the gut.
Cooking, mixing or chopping food usually allows more calories to be absorbed than what is stated on the label.
Again, of course, none of this cancels out PERE, but it does show that our accounting tools are far from perfect.
To be clear: a calorie calculator can be very useful, but it’s important to understand its shortcomings. When you do the calculation, it is a rough guess on which to base your calculations, but not at all the absolute truth.
Calories for PERE may not need to be counted
At Precision Nutrition, we sometimes use calorie counting to teach a client how to represent the amount of food they eat. And sometimes we can show them on their fingers (Zozhnik has translated the text about the “finger counting” technique – “Eating by the handful: an alternative way of counting calories”).
In women suffering from polycystic ovaries (about 5-10%) or going through menopause, hormonal changes can also affect energy balance.
So when using PERE, remember to visit your doctor and monitor your health.
Dilemma 3: “I only eat a thousand kcal, but I don’t lose weight!”
Usually these patients are in complete despair: metabolism isn’t working, native body isn’t working, PERE isn’t working. How else to explain it? And we have a couple of answers to that.
Reason 1: People eat more than they think they do.
Either they unknowingly overeat, or they count incorrectly. For example: They underestimate portion sizes (taking a spoonful of peanut butter with a big slide, adding as much as 90 kcal)
Tasting or eating out very high-calorie foods (leftover ice cream or pizza – plus 100 kcal).
Not writing something down in the diary straight away (e.g. a calorie drink drunk on the go) and then forgetting.
“Forgetting” to count treats that are embarrassing to admit to eating
You think it’s nothing? But a comprehensive study  found that people can underestimate up to 1000 kcal per day.
Reason 2: Going wild at the weekend.
After going through a stressful weekday, people go wild on Friday night (not you, of course, but some other people). So, let’s say some person is strictly eating 1500 kcal (on weekdays), keeping a deficit of 500. A weekend approaches… and:
For the average person, Precision Nutrition recommends eating 6 servings of vegetables, the size of your own fist. See the link for more details.
Or go with an intuitive approach.
Either way – whether we determine a specific number of calories or not – the amount of “incoming energy” is regulated, directly or indirectly. In short: PERE works without a calculator.
PERE is more complicated than it sounds
There’s no getting around the idea of PERE: If you’re not losing weight, you either need to reduce the amount of ‘incoming energy’ or increase the ‘expenditure’. But, as you may have already noticed, it’s all a bit more complicated than the usual ‘eat less, move more’.
You may also need to:
- Establish quality sleep to improve recovery, metabolism and regulation of hunger hormones.
- Turn to stress reduction techniques – meditation, deep breathing, nature walks).
- Increase the amount of non-exercise activity, e.g. parking your car further away, walking more, using the stairs instead of the lift, alternating between sitting and standing work.
- Replace high-intensity workouts with calmer workouts to improve recovery and reduce overall stress.
- Focus on the quality of food instead of the quantity: eat larger quantities of less calorie-dense foods.
- Operate on macronutrient composition, such as eating more protein and fibre; adding carbs while cutting back on fat, or vice versa.
- Experiment with the frequency and timing of meals according to personal preference and convenience.
- Keep a food diary for a while: make sure you actually eat as much as you think you do (at least approximately).
- Consult your GP and other specialists if the measures you are taking do not help at all.
- Sometimes the solution is on the surface, and sometimes it takes a lot of thought to find the right approach. PERE works if you are prepared to consider all the factors. Don’t want to?
Then here are 5 examples of when you think PERR doesn’t work. If you sort through each one, you’ll see that the principles of PERE are the same.
Dilemma 1: “Always eating the same, but suddenly I’m gaining weight.”
Can you guess what it is? More often than not, the ‘incoming energy’ and/or ‘expendable energy’ has changed, but in ways that you yourself haven’t been able to notice.
Portions became slightly larger due to mood, hunger or stress,
The number of calories absorbed increased due to a new medication, a health disorder or after over dieting.
Physiological changes may have resulted in less caloric intake during exercise and at rest.
Chronic pain may have led to a significant decrease in non-exercise activity.
Deterioration in sleep affected metabolism and the amount eaten.
PERE is still valid, you just haven’t tracked exactly how you started eating more and/or spending less.
Dilemma 2: “Damn hormones have ruined your metabolism! Getting fatter and fatter! Help me, help me!”
Of course, you want to blame all “fat” woes on hormones. And, of course, hormones are always involved in energy balance. But there’s a nuance: they can’t work outside of it.
In other words, people don’t gain weight from ‘hormones’, they gain weight anyway because of the caloric surplus that might have resulted from hormones.
For example, with menopause or thyroid problems, triiodothyronine (T3) and thyroxine (T4) levels drop and you gain weight. But this doesn’t invalidate PERE at all: the hormones have simply affected your ‘energy expenditure’. Your metabolism has worsened and you are spending less.
If you blame hormones, you might end up going down the wrong path, like spending a lot of money on unnecessary supplements or going on a super strict diet, which will make things worse in the long run.
If you understand the energy principles, you can adjust everything else: diet, movement, lifestyle and the right medication (prescribed by your doctor), taking into account the hormonal changes.
Dilemma 4: “Eat as much as I like and lose weight, that’s a diet!”
Probably the main reason for denying PERE. For example, someone you know has switched from processed foods to natural ones and finds that he eats a lot and the pounds come off. Then, of course, he believes in the power of nature. And yes, nature is cool, but PERE doesn’t go anywhere.
If one eats more vegetables (energetically not very dense, low-calorie ones), it is quite possible to stay on a deficit while getting full. Especially when you’ve come off a ‘processed’ diet of extremely calorie-dense fast food.
Or another example is keto. There too, they say “you can eat as much as you like”, and not vegetables at all, but meat, cheese, eggs, etc. It’s hard to call them low-calorie, and not so much with fibre. But they don’t lose weight either. The “ketchiki” assure us that it is a special diet different from others due to its “metabolic advantages”.
What actually happens is this:
- Fat and protein are great for satiety and reducing appetite,
- Strict restrictions exclude a bunch of processed carbohydrates (pasta, crisps, biscuits, etc.)
- Limited choice also reduces the appeal of the food allowed. Have had your sausage and don’t want to see any more.
- Most fatty liquids (sodas, juices, etc.) are also banned.
- The ketones in the blood suppress appetite too.
- As a result, people simply eat less (reducing the ‘energy supplied’).
Here you may ask: but if keto or veganism works, who cares about PERE? The answer is that PERE works for everyone, but keto or veganism does not.
All your friends can successfully lose weight on the next “best diet” and it doesn’t work for you personally for whatever reason – taste, lifestyle, activity level, hormones, etc. etc. And that’s the norm!
You can succeed on your favourite diet by developing healthy habits (positively affecting PERE):
- Eat about 80% full,
- Chew your food longer and more consciously,
- Choose the least processed foods (no to sausages and frankfurters!)
- Achieve maximum sleep quality ,
Learn to de-stress and relax.
Dilemma 5: “I want to gain, I eat until I can’t get any weight”.
Weight management is not just about losing weight; some people just can’t seem to put on the pounds they want. Again, one might think that PERE is no help here. But there is an explanation, even a couple of them.
People tend to remember extremes. Today, such a client will eat 6 meals and tomorrow he will have only 1-2 snacks, as he is still unable to recover from yesterday. But it is the first day of gluttony that will be remembered.
PERE invariably works, such people just can’t stabilise the ‘energy intake’. Solution: instead of sudden jumps (3000 kcal today, 1500 kcal tomorrow) aim for a daily calorie intake slightly higher than what you can maintain, and add gradually.
Following an increase in calorie intake, activity may also increase. When you’re full of energy (from a surplus), you also start to move around more: running around the office, talking on the phone, or adding more approaches to the gym.
This, as our trainers have noticed, happens very often with ‘hardgainers’.
The solution: monitor activity. If you notice it increasing, add more ‘incoming energy’. If you don’t have an appetite, use the heavy artillery – vegetable oils, animal fats and other calorie-dense foods.
3 ways to beat the system
When you realise and accept the inevitability of PERE, you may face one of the toughest obstacles. Namely, “But I can’t eat less than I do now!” Usually, people give up their unsuccessful attempts to lose weight because of this. Or keep searching for their magic diet. Here are 3 techniques to create and maintain a calorie deficit (even if you thought you’d never make it). Choose your own.
1. more protein and fibre
Fibre helps you eat more with fewer calories and protein helps you stay full longer between meals. This technique has been proven by both practice and research, but here’s the surprise: most people trying in vain to lose weight are still short on protein and fibre. And guess what? It’s not their fault.
It’s just that most people are constantly being told to cut back, cut down, cut back on their diets. All they’re taught is to throw out the “unhealthy” foods and calories to leave the “healthy” ones behind.
Try the opposite approach: add. If you focus on increasing protein (especially lean protein) and fibre (especially from vegetables), you’ll suddenly start to get full on the diet. And you’ll also lose interest in all the ultra-processed junk (it’s usually low in protein and fibre). You’ll end up eating fewer calories without much effort.
Start with simple steps: add another palm-sized serving of protein (chicken, fish, tofu) to one meal.
Imagine you are at a resort. You overslept and missed breakfast. Will you be disappointed? No, of course not: you’re having a great time, and lunch is close. And yet you’ll still be in deficit by a few hundred kcal. As you can see, it’s not hard at all in a pleasant environment.
And if the same thing happens in the weekdays (when you went on a diet to prepare for a holiday)? Obviously you’d think, “Missed the main meal, now starve all day!” Mornings are worse than usual, more stressed than usual, counting the minutes until dinner, all bad.
Notice, the deficit is the same in both cases, but perceived completely differently.
Could you change your mindset to behave the same way in the second case as in the first? I don’t mean that you should skip breakfast before you start your work day; but you could relax a bit and see the missed meal not as a deprivation and hardship of diet life, but as a conscious choice that leads to improvement. Then the calorie deficit won’t turn out to be such a big deal.
3. Add activity instead of cutting calories
If you prefer to “move around more” rather than “eat less”, here’s your option. Let’s say you need to keep a deficit of 500 kcal. This can be done, for example, as follows:
Energy intake: 2000 kcal / Energy expenditure: 2500 kcal / Deficit: 500 kcal.
Or: Energy Intake: 3000 kcal / Energy Consumption: 3500 kcal / Deficit: 500 kcal.
In both cases you achieve what you want, but in the second one you’re much better off eating!
There’s also a scientific benefit: studies show that when you combine a quality diet with a variety of sports activities (iron, OHP, active recovery, etc.) a higher calorie intake helps you gain muscle and burn fat. The fact is that increased physical activity doesn’t just “expend energy”, it also affects metabolism, spending more nutrients on muscle growth and storing less in fat cells.