Keto diet: emergency mode or the body's natural state?

The keto diet is no passing fad: for years it has divided those who defend it as a metabolic reset and those who see it as a risky experiment

In recent months, the debate over carbohydrate restriction has returned to the spotlight. The premise is simple: cut carbs almost entirely to force the body to burn fat for fuel, entering ketosis. But what looks like a quick weight-loss strategy hides a deeper conflict: is ketosis a natural state or an emergency system that should not be sustained long term?

The 'emergency system' argument

The most critical view holds that ketosis is a survival mechanism for periods of scarcity, not a sustainable regimen. It draws on evolution: the human body is designed for a diet low in simple carbohydrates, but not for eliminating them completely. According to this view, relying on ketosis as a routine is like driving with the fuel warning light permanently on. Advocates, on the other hand, argue that metabolic flexibility —being able to use glucose or ketone bodies interchangeably— is the real goal, and that continuous ketosis is unnecessary.

Real results: weight loss and the sugar 'monkey'

Those who have trinc the keto diet strictly (limits of 20 grams of carbs per day for six months) report significant fat loss and a drastic reduction in appetite, to the point of being able to fast for 24 hours without feeling hungry. However, they admit the first days are tough: headaches, fatigue and a powerful sugar and carb 'monkey' on their back. The addiction to processed carbohydrates is real, and breaking it requires a withdrawal period that many do not get through.

The ignored side effects: constipation and the vegetable trap

A recurring problem is constipation. Cutting out fruit, grains and legumes drastically reduces fibre intake. Many people's solution is to include kiwi, coffee or leafy greens, but with caveats: cooked vegetables (such as carrot, pepper or onion) release simple sugars when heated, which can raise the glycaemic index and break ketosis. So they are only recommended raw or lightly grilled. A detail that turns the diet into a constant puzzle.

Sustainability: the Achilles' heel of the keto diet

The most widespread criticism is that keto is not sustainable in the long run. Those who have trinc it for years admit it is a social 'drag': eating out is nearly impossible, and the rigidity leads some to develop an almost cult-like relationship with food. It is also pointed out that muscle loss can occur if the diet is not combined with strength training and sufficient protein intake. Natural bodybuilders, for example, start their cutting phase eight months before a competition, knowing that rushing does not work without external help.

The debate remains open. While some see keto as a tool to reset the metabolism and break sugar addiction, others consider it an unnecessary detour that forces the body into an emergency state. Two years after this discussion began, the balance between results and risks is still unsettled.