Fad diets: here is everything you need to know

How many times have you refused your favourite sweets or snacks? Did you ever skip a meeting with friends or family because you’re on a diet and did not want to be feel tempted? We all know food is the foundation of life. In addition to its biological function – it gives us energy and is vital to our survival – the pleasure of eating unites people from different corners of the world as few other things do. However, when the goal is to lose weight, there is a tendency to look for quick fixes centred around food “austerity”. Does it really have to be this way?

Fad diets are strategies, usually temporary, meant to help you lose weight quickly – but they often don’t have a scientific basis to attest to their long-term health benefits or effectiveness. The flat-out exclusion of certain foods or food groups makes most fad diets nutritionally unbalanced and unsafe.

Restrictive diets may result in greater initial weight loss, but they can also cause endocrine, metabolic and behavioural changes, as well as unsatisfactory long-term results. Technically speaking, what usually happens on a restrictive diet is a reduction in leptin (the satiety hormone) and an increase in ghrelin (the hunger hormone), increasing the likelihood of binge eating. In addition, weight loss is usually achieved through the loss of body fluids and lean mass, rather than the desired loss of fat mass.

Fad diets often cause a micronutrient deficit, which can lead to symptoms such as headaches, fatigue or hair loss, as the body goes into energy-saving mode. Their temporary duration also leads to greater difficulty in implementing healthy eating habits.

Along with the growing concern about nutrition, the list of fad diets continues to grow. This is what science tells us about the most popular fad diets:

The Palaeolithic diet basically says you should eat more fruit and vegetables and stay away from processed foods, which is obviously sound advice. But it can also lead to an excessive daily intake of fat and protein, as well as nutritional deficiencies and an imbalance in the intestinal microbiota, since it excludes cereals, legumes and dairy products. It also has a high economic and environmental cost.

Foods such as bread, cereals, rice, pasta, potatoes, legumes and practically all fruit are excluded.

The ketogenic diet is successfully used to treat epilepsy and has shown potential in obesity treatment. Although studies show a significant reduction in body weight, Body Mass Index and percentage of fat mass, it is not clear that the reason is the state of ketosis or energy restriction.

This diet can cause fatigue, moodiness, irritability, constipation and headaches, as well as nutritional deficits, meaning it should be accompanied by supplementation. More studies are needed on the impact of the ketogenic diet on hormonal changes, the reproductive system and the microbiota. Only then will it be possible to establish the ideal ratio of nutrients, energy intake and concentration of ketone bodies, to maximize results without compromising health.

They usually last for a short period (about two weeks) and have a low energy value (usually less than 800 kcal/day).

Detox diets fail in their main goal, as there is no scientific evidence to support the idea that they boost the body’s toxin elimination capabilities. Any weight loss is usually temporary, as much of that will be water and muscle mass. It also does not lead to good eating habits.

The most common form of intermittent fasting is time-restricted eating, which consists of fasting daily for 16 to 20 hours, and then enjoying a so-called “normal” diet for the rest of the day. Common symptoms include weakness, headaches, difficulty concentrating, or low blood pressure, especially in the first days.

Unlike most fad diets, intermittent fasting has shown promising results and some benefits, particularly in terms of weight loss, cholesterol reduction, blood pressure and inflammatory parameters. However, only a handful of studies have been made on its long-term effectiveness. The studies that do exist, show similar results in terms of weight loss and the health when compared to a conventional weight loss diet, i.e. one with continuous calorie restriction. Although it is not a solution for everyone, it could be an approach to consider in specific cases, provided it is properly monitored by a nutritionist.

In any case, intermittent fasting is not suited for children, pregnant or breastfeeding women, the elderly, diabetics, immunosuppressed people, people with hormonal disorders or eating disorders.

The answer is so simple it’s hard to believe. To lose weight, all you have to do is eat fewer calories than your body expends. In other words, you have to expend more calories than you consume – also called a “negative energy balance”. Along with diet, it’s essential to fight a sedentary lifestyle. Very simply, losing weight depends on a balanced diet – the positive effects of which are not only on physical health, but also on mental health – and physical exercise.

Find out 6 tips to reduce fat and 8 tips to reduce sugar in your diet.

So, what is the best diet for losing weight?

The answer doesn’t lie in a specific diet, but in a balanced, sustained diet. This doesn’t have to involve radical restrictions or pain – diversity is the main characteristic of a balanced diet, so there are no “bad” foods.

The best diet for losing weight is one in which:

• The energy balance is negative (the energy expended is greater than that consumed);
• There is a nutritional balance, i.e. there is no risk of nutritional deficit, that can compromise health;
• The effects are scientifically proven.

Any diet for weight loss should be carried out under a nutritionist’s supervision. These professionals will recommend a bespoke diet, adjusted to your routines and characteristics. There is also a food education component to consider, key to enable good habits to be improved and maintained over the long term. Although the results may not be immediate, the change in your body is taking place gradually, and you will be able to maintain over time.

The best diet also involves choosing the right products, according to your needs – something you can do that by learning how to read a food label.

Fad diets may arouse curiosity, but it’s worth remembering that the good old Mediterranean Diet is battle tested in the fight against obesity. It has also shown enormous potential in preventing various chronic diseases. By promoting food diversity, sociable moments around the table, and by prioritizing water consumption and regular physical exercise, it is the foundation of a healthy lifestyle. It is one example of a balanced diet that does not harm your health and, if you’re not already familiar with it, it is worth trying out.