You enjoyed the holidays, but would like to get off to a good start. And therefore, lighten up on the scales at the start of the year? If the intention is laudable, it should not open the door to overly restrictive diets. Here are 7 to avoid, according to experts.
Why strict diets are a bad idea
For Vanessa Bedjaï-Haddad, a dietitian nutritionist regularly consulted by True Medical, the problem is clear:
“The diet as we understand it, a constraint to lighten up quickly, should be avoided if it does not allow lasting weight loss”.
Extreme or very restrictive diets certainly lead to rapid results. But often also nutritional deficiencies, a slowdown in metabolism, increased fatigue and… an almost guaranteed yo-yo effect. Result: we lose quickly, but we recover even faster.
The keto diet: too rich, too restrictive
Very popular in recent years, the ketogenic diet is based on a strong reduction in carbohydrates, compensated by a high consumption of fats.
For the specialist, this is not the miracle solution: “For me, it’s not a very “smart” diet because it contains too many foods of animal origin, foods rich in saturated fat but not enough fiber, vitamins or minerals.
A type of diet that often generates more frustration than benefits.
Meal replacements: practical, but frustrating
Bars, shakes, diluting powders… Meal replacements are making a comeback with modernized formulas. However, Vanessa Bedjaï-Haddad remains cautious:
“It is also not ideal, because this form of meal directly deprives you of any social connection, and places you apart. It is therefore a diet which still creates frustration.”
In addition, they are often poor in fiber and insufficient to last over time, they can accentuate hunger and discouragement.
Eliminating food without medical reason: useless
Totally eliminating carbohydrates, gluten or lactose without a precise diagnosis is another common mistake.
“When there is no medical necessity to remove a food group, there is no point. The body needs all foods, in a balanced way“.
The challenge is not to ban, but to learn to dose in frequency and quantity.
The monodiet, or the juice cure: a false rest for the body
Eating only one food for several days (soup, fruits, vegetables) is often presented as a “digestive break”. A preconceived idea, according to the nutritionist:
“If you eat healthy and balanced, your digestive tract will be very well. You will not need to deprive yourself.”
She warns against fatigue, deficiencies and rapid regain of lost weight. This is also the case if you opt for a juice cleanse, a falsely healthy method. Even over a few days, these cures can:
- Disrupt the intestinal microbiota;
- Increase inflammation;
- Cause fatigue, dizziness, gas and food cravings.
Their main problem: they are low in fiber and often high in sugars, which promotes blood sugar spikes.
The low GI diet: not absurd, but too restrictive
Monitoring blood sugar peaks can make sense, but as long as you don’t go overboard.
“It’s not totally stupid… but from there to only selecting foods with a low glycemic index, I’m not convinced that it’s of any real interest.”
The carnivore diet: too restrictive to be healthy
Finally, the carnivore diet completely excludes foods of plant origin and relies solely on animal products.
While it may cause rapid weight loss at first, it is very nutritionally unbalanced.
This type of diet is poor in fiber, vitamins (C, folate), essential minerals such as magnesium or calcium.
What to do instead to lose weight sustainably?
Losing weight can improve your health, if you do it wisely. January miracle diets often do more damage than they provide solutions. Vanessa Bedjaï-Haddad’s message is unequivocal for a lighter start to the year.
“The idea is not to subscribe to this or that fashionable diet, but to find a balanced diet that allows us a long-term routine.”
The right strategies
- Aim for gradual weight loss (500 g to 1 kg per week);
- Eat a varied diet, with proteins, fiber, good fats and quality carbohydrates;
- Favor raw and minimally processed foods;
- Maintain a social life and enjoyment at the table;
- Move regularly, without excess or guilt.
And if you really want a lasting effect at the start of 2026 (a good resolution), avoid too-good-to-be-true promises seen on the networks, learn to think in the long term, and possibly seek advice from a health professional for appropriate advice.