You read that right: burning fat and losing fat are not automatically the same. And for a successful cut it is important to be aware of the difference between the two.
1. During a day we burn fat at different times, while at other times we store fat.
2. If we use a relatively large amount of fat as an energy source during an activity (and therefore burn a lot of fat), the body will use a relatively large amount of carbohydrates (glucose and glycogen) as an energy source at another time.
3. Whether you lose fat depends on your energy balance throughout the day. You only lose fat if there is an energy deficit, or a negative energy balance (calories in, calories out).
4. If you’re not losing weight, you’re not experiencing an energy deficit, even though you may think you are.
5. It doesn’t matter whether you follow a diet that is high in fat or high in carbohydrates. While there are differences in fat burning and fat storage, the net effect is the same, which is the difference between calories in and calories out.
6. It doesn’t matter whether you do cardio that burns a relatively large amount of fat, such as cardio on an empty stomach or cardio in the ‘fat burning zone’. At a later moment you will then consume a relatively large amount of carbohydrates. The net effect is the same, namely the difference between calories in and calories out.
FAT BURNING
Fat burning is a physiological process that takes place to generate energy in the body. Fats (either from food or stored in the body) are oxidized (burned, so to speak) and converted into energy. Nothing more and nothing less.
FAT LOSS
However, whether you lose fat is determined by the balance between fat storage and fat oxidation: you lose fat if the degree of oxidation is greater than the amount of fat that is stored.
In other words: to lose fat you have to create a negative energy balance over a longer period of time. At the end of that period, you will have consumed more energy than you received through your diet.
We express the amount of energy you ingest through food in calories – kilocalories (kcal) to be precise.
And the period we are talking about is usually a day, because we look at many things on a 24-hour basis. But to actually lose a lot of fat, you have to maintain such a negative energy balance for a much longer period of time.
WHY THE DIFFERENCE MATTERS
The degree of fat burning is often used as an argument for a particular weight loss method. But if you know that the amount of fat you burn at a given moment says nothing about the fat loss, that argument falls. We give three examples.
LOW CARB/HIGH FAT VS HIGH CARB/LOW FAT
Many diet and fitness gurus recommend following a high-fat, low-carbohydrate diet for fat loss. The low carbohydrate intake keeps the level of insulin (the hormone that supplies your body cells with glucose) low, making your body easier to burn fat, the argument goes, which is correct in itself.
However: eating more fat also means that your body stores fat more easily. By far the largest part of the fat storage comes from the fats in our diet, because fat storage from carbohydrates is a relatively difficult process [ i ] .
The other way around: if you follow a high carb/low fat diet, you will burn less fat due to the high insulin level, but at the same time you will also store less fat.
The net result is therefore more or less the same. There is therefore always no hard evidence for the often heard claim that low carb/high fat is more effective for fat loss [ ii ] . Not the other way around either. A large – scale study lasting twelve months endorses this [ iii ] , as do dozens of other studies [ v ] . And a large meta-analysis by Menno Henselmans shows that it makes no difference to training performance whether you go high or low in fat [ vii ] .
Whether you mainly cut carbohydrates or fats in your diet is usually purely a matter of personal preference: you choose the diet that is easiest for you to stick to.
Our preference is to stay as high as possible in the carbohydrates during the cut and to concentrate them as much as possible around the training. After all, carbohydrates are important for muscle growth for various reasons. Of course, fat is also important, but you don’t need more than 0.5 to 1 gram per kilogram of body weight per day in the cut.
So our distribution of macronutrients in the cut is:
- energy (kcal): maintenance minus 20-25%
- proteins: 1.8-2.7 g per kg body weight
- fats: 0.5-1 g per kg body weight
- carbohydrates: the rest
CARDIO ON AN EMPTY STOMACH
Another popular piece of advice is to do cardio on an empty stomach, because you burn more fat that way than when you train on a full stomach.
That last one is correct. After all, on an empty stomach, early in the morning for example, your body has little energy from carbohydrates (glucose and glycogen) at its disposal, so that it will almost immediately use fat mass to obtain energy.
But we have seen that fat burning and fat loss are two different things. And that is also apparent now: if you consume a relatively large amount of fat during a cardio session, your body will use a relatively large amount of carbohydrates (glucose or glycogen) at another time. Viewed throughout the day, for fat loss, it makes no difference which energy source you use at what time.
For bodybuilders, morning fasted cardio may even be detrimental, as levels of the muscle-degrading hormone cortisol are highest in the early morning [ vi ] .
CARDIO AND THE FAT BURNING ZONE
Yes, if you’re doing cardio, there’s such a thing as a fat burning zone, or actually aerobic training zone. It is between 65 and 75 percent of your maximum heart rate.
And it’s also true that you burn a relatively large amount of fat in that zone: about 50 to 60 percent of the energy you use by training at this relatively low intensity is supplied by fat. This is because more oxygen is available when exercising at a low intensity. And the use of fat as an energy source requires more oxygen than is the case with carbohydrates.
Now it is nice if you burn a relatively large amount of fat during that cardio session, but at other times of the day your body will use a relatively large amount of carbohydrates as an energy source. For the total picture, your energy consumption over 24 hours, it makes no difference [ iv ] . Just like you shouldn’t do at least 30 minutes of cardio for it to have an effect on fat loss – another persistent cardio myth.
By the way, there is nothing wrong with training in the fat burning zone. It’s fine if you can’t or don’t want to train more intensively.
Remember: exercise leads to energy expenditure, whether that exercise is long or short, and whether the intensity is high or low. And that energy consumption counts for your total energy balance, so it can contribute to an energy deficit and therefore to fat loss. See further our article on cardio myths.
CALORIES IN, CALORIES OUT
We have seen that fat burning occurs at different times of the day, depending on physical activity and the energy sources available at the time. However, fat loss only takes place if there is an energy deficit throughout the day.
Is fat loss as simple as calories in, calories out ? Yes. And is a calorie a calorie? Yes. Just like a meter is a meter, and a liter is a liter.
One important ‘but’: the calorie count of a food product does not say everything about the actual amount of energy that product provides you. Food with a lot of protein and/or fiber has an increased thermogenesis. Thermogenesis is the energy your body needs to process food. This can be up to 10% of your total consumption. If you eat a food product of, for example, 200 kcal, of which 20 grams of proteins, you will have less energy left than if you eat a product of 200 kcal with only 5 grams of proteins.
Furthermore, the satiety level of food also plays a role: although not for the actual energy supplied, but for your feeling of hunger. If you eat a lot of food with a high calorie density, you make dieting unnecessarily difficult.
“I’M NOT LOSING WEIGHT!”
Increased thermogenesis and other special aspects of energy consumption, such as the afterburn effect during strenuous exercise, mean that you can never calculate your energy balance completely accurately, even with a calorie app. In addition, your maintenance level is always an estimate, no matter how accurately you try to calculate it.
As a result, it can happen that you do not lose fat, even though you think you have a negative energy balance. Apparently you don’t have that and you will have to cut even more calories to actually lose fat.
Also remember that during a long-term diet your maintenance level decreases under the influence of metabolic adaptation. This means that in the long run you have to eat even less and/or exercise (even) more to maintain the energy deficit.
In short, if you do not lose weight, you are not in an energy shortage. Instead of insisting that this is the case at high and low, it is better to adjust your diet and/or start exercising more.
SUMMARIZED
During a day we burn fat at different times, while at other times we store fat. If we use a relatively large amount of fat as an energy source during an activity (and therefore burn a lot of fat), the body will use a relatively large amount of carbohydrates (glucose and glycogen) as an energy source at another time.
Whether you lose fat depends on your energy balance throughout the day (calories in, calories out). You only lose fat if there is an energy deficit, or a negative energy balance. If you’re not losing weight, you’re not experiencing an energy deficit, even though you may think you are.
It does not matter whether you follow a diet that is high in fats or high in carbohydrates. While there are differences in fat burning and fat storage, the net effect is the same, which is the difference between calories in and calories out .
It doesn’t matter whether you do cardio that burns a relatively large amount of fat, such as cardio on an empty stomach or cardio in the ‘fat burning zone’. At a later moment you will then consume a relatively large amount of carbohydrates. The net effect is the same, namely the difference between calories in and calories out .
REFERENCES
- [ i ] https://examine.com/nutrition/will-carbs-make-me-fat/
- [ ii ] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6224925/
- [ iii ] https://pubmed.ncbi.nlm.nih.gov/29466592/
- [ iv ] https://pubmed.ncbi.nlm.nih.gov/23313101/
- [ v ] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3530364/
- [ vi ] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3475279/
- [ vi ] https://pubmed.ncbi.nlm.nih.gov/29466592/