No matter how hard they work, some people lose no body fat while others get lean without much work at all. Within the educated exercise science community, there aren’t many people who preach the calories-in/calories-out explanation. The reason for this is empirical science. When you hook a respiratory exchange measurement device to a person, you can directly observe how much of the citric acid cycle is served by sugar and how much is served by fat.
And, in even an extremely hypocaloric deficit scenario there is no obligation to ever use stored body fat. Anyone who’s studied metabolic testing knows this. The liver will continue keeping up with the energy needs via gluconeogenesis while proteolytic catabolism churns away. That is, you can eat less than you use and lose NO body fat. You will lose weight: organ tissue, muscles, bones. You won’t lose fat. Afterward, you will regain the lost weight, but only in fat, not lean tissue.
It seems unbelievable at first. And then, after you start observing many many people who just straight up never burn fat, you have to defer to science. We measure this, by the way. This isn’t opinion.
I’ve observed tests where someone SEATED, not exercising, is at 100% sugar burn. That “shouldn’t” happen until a full-out sprint. It happens for some people at rest. This person will never get leaner through more exercise and dieting. They will lose weight. But they won’t get leaner, ever, until we fix the energy propensity issue.
This takes very substantial troubleshooting. We have to move the person’s intake UP. We have to restore that person. We have to drop their stress and activity DOWN. Then, once a certain set of hormonal variables are righted, they have a chance at burning fat. Prior to that, body fat percentage will almost always go UP every time their body weight goes DOWN.
This is no small deal, by the way, because we have this tendency to think people are morally failing when they don’t lose fat. But it has little to do with willpower. In fact, a lot of people struggle to get leaner because they ARE following the bro science of inexperienced influencers and coaches who’ve maybe never observed or administered a single metabolic test.
There is some evidence that a full fast will help reset this. That is, you will clear glycogen to a level where one ought to be obligated toward SOME fat burn. In low caloric intake, however, that can never happen. Reread that. In a fat-burn-resistant person, reducing intake will NEVER obligatorily result in using more fat. Never. Never. Never.
It’s a big project. There is a lot of building and rebuilding to do first. There’s a lot of managing stress to do first. There’s a lot of regular strength training to incorporate first.
But don’t guess. Test. You can schedule an active metabolic assessment at a lot of places nowadays. You’ve already seen that effort does not equate to results. Schedule a test at a local clinic, hospital, exercise science department at a university, or fitness facility. Sure. Sometimes, we’ll find that you burn fat just fine. For those people, cool. Just eat like a grownup and move. But in an increasingly higher percent of the populace, we find “anomalous” testing numbers. It soon won’t be anomalous.