Doctors often tell skinny-fat people they’re at a “healthy” weight, but in reality, they have so little muscle that their fat simply offsets that weight. In other words, their weight is normal on paper, but their body composition is trash.
A few key things contribute to this, but the main cause is poorly-executed dieting cycles. Most people focus on weight loss, which leads them to unsustainable forms of dieting. These plans usually have little protein (or calories in general) and are frequently accompanied by excessive cardio with no strength training.
The result? They lose weight and precious muscle mass in the process. Muscle – and the process of building it – is calorically costly. It also increases metabolism and acts as a glucose disposal site. Losing muscle makes your dieting efforts even harder.
Once you inevitably stop the diet, you’ll be a smaller person with lower caloric needs. (Bigger bodies require more calories for daily activity.) You’ll have lost muscle too, which will also decrease energy expenditure. So even if you eat the same amount of calories as before you started the diet, you’ll now be in a caloric surplus, and your body will be ready to store those calories.
Not only will the caloric surplus cause fat gain, but most people who’ve been dieting hard are also tempted to binge after the diet. The caloric surplus starts off with a bang.
At this point, the dieter will have more fat and less muscle than before they started. Out of desperation, they’ll often look for an even more extreme diet with even worse effects. The cycle repeats, and the person’s body composition gets exponentially worse each time because they never learned their lesson.