NUTRITIONISTS at the Quirónsalud private hospitals in Torrevieja (Alicante province) and Murcia have warned of the dangers of following so-called 'celebrity diets'.
“They can put your physical and mental health at risk, especially as they are not supervised by specialists,” says dietician Dr Carolina Pérez.
“Weight loss is, and needs to be, a slow process and if you lose a lot of weight in a short time, you're also losing other types of tissue such as muscle and bone.
“You should never try to lose more than a kilo a week (2.2lb) and no more than five to six kilos (11lb to 13.2lb) in a couple of months,” the nutritionist stresses.
Although 'celebrity diets' are tempting, because they involve 'little effort for fast results', they involve cutting out entire necessary food groups, and are based entirely on reducing calories.
This means the dieter suffers a lack of energy, which the body compensates for by destroying proteins – leading to a major loss of muscle mass and ketone bodies, highly-acidic particles released by the liver, appearing in the bloodstream and urine.
The result is a 'serious danger' to vital organs, says Dr Pérez.
Loss of minerals such as calcium and potassium, loss of vitamins – some of which are crucial in puberty and pregnancy, for example – serious alterations in the body such as metabolic disorders and cardio-vascular, liver or kidney damage can ensue.
In psychological terms, these diets can cause anxiety, insomnia and irritability, and can lead to eating disorders such as anorexia or bulimia.
“Losing weight healthily and safely means following a personalised and supervised diet with the help of a nutritionist and a psychologist, giving you a proper dietary education and encouraging healthy eating habits,” says Dr Pérez.
Diets based on high levels of protein and low, or non-existent carbohydrate intake are aimed at reducing appetite, but are the most risky for health – they include excessive amounts of meat and animal fats, which can lead to fast weight gain long-term.
Also, high-protein, low-carb diets can lead to chronic illnesses such as osteoporosis, kidney stones, kidney failure, obesity, heart and circulation disorders, cancer, and overall, a higher risk of premature death.
The macrobiotic diet – aimed at seeking an 'emotional and spiritual balance' through food, comprises 10 different régimes: the first five include gradually decreasing quantities of animal products and the remaining five are exclusively vegetarian or vegan.
Although Spanish nutritionists are beginning to come around to the idea that a vegetarian or vegan diet is perfectly healthy if followed correctly, macrobiotic versions are highly-restrictive in their intake of food in general, leading to deficiencies in iron, calcium, beta-carotene, protein, and vitamins A, D, B12 and D, causing anaemia, severe calcium loss, and general malnutrition.
Another 'celebrity diet' Dr Pérez mentions is the 'Saphiro', which uses pictures to guide those who follow it – for example, a slice of buttered toast may contain the same amount of calories as a banana or a quarter of a melon – and aims for a calorie consumption of fewer than 1,800 a day.
Whilst it is simple to follow and does not ban any food whatsoever, it is not recommendable because it is purely based upon calorie-cutting.
The Factor 5 diet, aimed at losing weight in just five weeks, only includes two days of strict dieting a week and otherwise includes five meals a day.
This way, the dieter does not suffer hunger or withdrawal symptoms and is less likely to lapse, and the recipes for the meals involve five ingredients and are simple to make.
The only one that factors in physical exercise, the Factor 5 diet is nevertheless no safer than the others – children, teenagers, pregnant women, anyone suffering depression or an eating disorder, or anyone with a kidney disorder should not follow it, because of the dangers involved in the high-protein diets consumed during the two 'restricted' days.
Exercise is crucial when losing weight, because it helps recover muscle mass lost through dieting and increases metabolic efficiency, meaning the body learns to burn off calories more quickly even during times of rest, Dr Pérez explains.