“Slimming diets tend to be very commercial and most of them have very little scientific basis”

Francisco Miralles.
Francisco Miralles. / S. SALAS
  • The doctor of Internal Medicine gave a talk on obesity as part of the 'Medac Talks' series in Malaga on Thursday

  • Francisco Miralles Specialist and medical director of Asisa in Malaga

Excess weight has become a public health problem in western society. Francisco Miralles, a specialist in internal medicine (he sees patients at the Gálvez Clinic) and medical director of the Malaga branch of Asisa, spoke on Thursday about the factors which lead to obesity as part of the 'Medac Talks', organised by the Medac Institute in collaboration with SUR. The conference took place at the Medac offices, in Avenida de Velázquez. Dr Miralles says that many diets have very little scientific basis.

Why are so many people becoming obese these days?

There are several factors which can influence weight gain but which people don't often consider: genetics, sleep, social relationships, obesogens, microbiota (intestinal bacteria), inadequate meals and a sedentary lifestyle.

Which has the greatest influence on weight gain, genetics or lifestyle habits?

It has been shown that genetics are very important. Studies have been carried out on adopted children and have shown that between 30 and 60 per cent have a genetic conditioning which makes them resemble their biological parents. In monozygotic twins, who are genetically identical, the percentage is even higher. Although it is true that those twins share not only their genetics but also lifestyle habits: they eat the same foods and take a similar amount of exercise.

Human beings seem to have passed from being accustomed to periods of hunger to eating in excess and not bothering with physical exercise.

There is a clear obesogenic environment now. The genetic element is a conditioning factor, but not a determining one. We live in a society which tends towards obesity. People consume too many calories, are far too sedentary and there is a series of factors which result in us eating much more than we expend. Our forefathers didn't have those and, also, their work was much more physical.

Of the subjects discussed at the conference, which do you think drew the most attention?

I think probably the obesogens, which are chemical substances that work as metabolic disruptors. In other words, they intervene on the adipose tissue and increase the number of cells and their size. They also produce hormonal alterations and affect control of satiety and appetite. All that means that a person is more likely to put on weight. It's a vicious circle. The more obesogens you eat, the more fat you have, and the more fat you have, the more obesogens you store. These chemical substances are in things we use every day, like, for example, plastic water bottles.

Is there any way the obesogens can be controlled medically?

This is a very hot subject, and is something very recent. The authorities are just starting to legislate now. The Americans are very concerned about it.

What relationship is there between plastic water bottles and increased obesity?

The plastic releases obesogenic particles which dilute in the water. That's why they say plastic water bottles shouldn't be reused. Another recommendation is that foods should not be heated in a plastic container, always in glass. There are also obesogenic substances in herbicides and insecticides, which means that they pass into the food cycle. We end up eating them .

Are diets effective in helping people to lose weight?

People tend to go a bit crazy when it comes to diets. No matter what diet you follow, you will usually lose weight. What's important is to stick to the diet. We have the best diet in the world, which is the Mediterranean one. What is important is to continue with the diet and support it with physical exercise. There is a great deal of interest in different diets, but they are very commercial and most of them have little scientific basis.

Most people believe they will lose weight if they diet, but they're not interested in taking exercise.

Exercise by itself won't make you lose much weight, but it is important in maintaining weight loss. The essential thing is to change your behaviour and modify your way of eating and moving, because if you don't, even if you are on a strict diet, in a short time you will gain more weight than you lost.

Do people ask for professional help when they want to lose weight?

In general, no. Very few people ask a professional for advice. With social media and the internet it is easy to acquire information, but unfortunately a lot of that information is false. People tend to rely too much on the internet, and not enough on professionals.