The moment the Spring Festival ends and you step on the body fat scale —

your heart sinks.

Up 1.5 kg? Up 2.5 kg?

Or... too scared to look?

But before you spiral, here is a fact that may make you forgive yourself on the spot:

Those extra kilos may not be what you think they are.

For many people, a few extra kilos after the holiday trigger one immediate thought: "That's it — it's all fat." Physiologically, though, it is not that simple.

Gaining 1 kilogram of pure fat requires a surplus of roughly 7,700 kcal. Eating 500 extra kcal a day through a week of Spring Festival is easy enough, and by week's end you may indeed have stored around a quarter kilo of fat — but that accounts for only a small part of the jump on the scale.

So where does the rest come from?

Rice, noodles and dumplings take turns on the table over the holiday, and carbohydrates badly overshoot. The body converts surplus carbohydrates into stored glycogen — and here is the catch: every gram of glycogen stored carries 3-4 grams of water along with it. That alone can add 0.5-1 kg.

Holiday cooking needs no explanation: heavy on salt, oil and MSG. To keep electrolytes balanced, the body clings to water for dear life. Studies show that a high-sodium diet can add 0.5-1.5 kg within 24-48 hours.

All that meat and rich food means too little dietary fibre, and with a disrupted routine the gut slows down. The "inventory" still sitting inside can contribute close to another half kilo.

A high-fat, high-sugar diet raises inflammatory markers (such as IL-6 and TNF-α) within days, and an inflammatory state itself causes mild fluid retention.

So the "fat" you are seeing is probably more than half water and metabolic stress.

And that is the good news.

If your body's capacity to recover falls short, this "false weight" can gradually turn into real fat.

Especially when the following occur together:

Research shows that insufficient sleep can raise the hunger hormone ghrelin by about 20% and lower the satiety hormone leptin by about 15%. The result: you want to eat more and find it harder to stop. Sleep deprivation also raises inflammation in its own right.

After a short spell of overeating, the body switches on a series of adaptive mechanisms. Expanding fat cells release pro-inflammatory factors, putting the body into a state of low-grade inflammation — and inflammation reduces the efficiency of fat mobilisation. Put simply: it is not that you are not trying; it is that your body is in a "not in the mood to burn" state.

Short-term dietary change reshapes the profile of gut fermentation products, which in turn affects how much energy is absorbed and how lipids are metabolised. That is why some people bounce back in three days while others carry the extra weight for a month.

Rather than starting a diet right away, ask a few questions first:

Is it fluid retention, or genuine fat?

Is it inflammation, or simply too much food?

Is it declining metabolic efficiency, or is your gut microbiota working against you?

Weight is only the outcome; metabolic pathways are the cause.

     Increase protein intake and cut refined carbohydrates