In recent years, intermittent fasting has become one of the most popular methods for losing weight and “improving health.” On social media, it is presented almost as a magical solution: You eat for eight hours a day, fast for 16 hours, and don’t have to give up anything.
Sounds perfect, right? But behind the impressive headlines lies a much more complex picture.
What is intermittent fasting, anyway?
The most common method is 16:8 – meaning, you eat during an eight-hour window (for example, between 12:00 and 20:00) and fast for 16 hours. There are also other versions: Fasting two days a week (the “5:2 method”), or skipping meals. The main idea is to give the body a “rest” from food for long periods of time.
During fasting, insulin levels in the blood drop, the body begins to use fat stores, and some claim that this process contributes to weight loss and improved cell function. But as with many nutrition methods – reality is a little different from the headline.
What really matters – not how many hours, but how many calories
The main factor in weight loss is simple: Calorie balance. If you eat 5,000 calories a day and burn only 2,000 – you’ll gain weight, even if you eat everything within two hours and fast for the next 22. Therefore, anyone who claims that “I can eat anything and lose weight because I fast for 16 hours” – probably doesn’t quite understand the math of calories.
In practice, most people can lose weight with this method, but not because of the magic of fasting itself, rather because they eat during fewer hours and therefore, theoretically, consume fewer calories.
Reducing eating time usually naturally leads to eating fewer cookies, fewer snacks, and fewer unnecessary late-night meals. On the other hand, this isn’t always accurate. This method doesn’t come with a meal plan, only time instructions – when to eat and when not to. Many people simply continue eating the same things, just limit their eating hours and wait for results.
I’ve already spoken with listeners who continued to eat chips, schnitzel, bourekas, and even wafers – they just started eating them at 12:00 and finished at 20:00. Obviously, they didn’t improve their health, nor did they save even one calorie.
Does it benefit health?
Some studies show potential benefits, but they are not conclusive:
A study published in Cell Metabolism showed that fasting 16 hours a day for 12 weeks led to an average weight loss of about 3% and a slight improvement in blood pressure.
On the other hand, a study from Johns Hopkins University found that the effect on blood sugar, cholesterol, and body fat levels was almost negligible when total daily calorie intake remained the same.
Another study conducted on menopausal women found that prolonged fasting may cause fatigue, mood swings, and even loss of muscle mass.
The current scientific consensus is that intermittent fasting can be a useful tool – but only if combined with a healthy diet, if it fits the person’s lifestyle, and if it does not lead to overeating during the permitted hours.
Who is it suitable for, and what’s the biggest mistake?
Many mistakenly think that coffee and tea “don’t break the fast” – even without sugar – but the caffeine in coffee and tea activates the liver and cancels the metabolic rest state that fasting is meant to produce.
Anyone who wants to truly fast metabolically should avoid any beverage containing caffeine, even if it’s calorie-free. Water, however, is allowed and even recommended during the fast.
Intermittent fasting can suit people who prefer a fixed, clear structure – those who can easily give up breakfast or dinner and are not prone to snacking. But it is not recommended for children, pregnant women, diabetics treated with insulin, or those suffering from eating disorders. Also, for anyone feeling weakness, irritability, or headaches during fasting – there is no obligation to “push through for the sake of health.”
In conclusion, I don’t recommend this method, and I don’t recommend anyone eat according to the clock. It’s much more important to learn to listen to your body and what it signals to you. Intermittent fasting can help with weight loss – but not because of the “magic of the hours,” rather because of the reduction in food quantity. What truly matters is what you eat during meals (and not when).
Vegetables, quality protein, whole grains, healthy fats – and not bourekas, chips, and hamburgers. In the end, our body doesn’t “count hours.” It counts calories, food quality, and balance.