Treatment of Obesity

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The treatment of the obesity must be integrated and multidisciplinary in order to achieve and maintain a healthy weight. Weight losses of at least 5-10% in a period of 6 months improve and control the appearance of other diseases (comorbidities) associated with obesity.

The initial treatment of obesity includes changes in eating habits and an increase in physical exercise. Together with these strategies and, depending on the level of obesity, drugs could be administered or bariatric surgery chosen with the aim of boosting the weight loss.


Diet. There is no single diet pattern to lower weight. Together with the dietician-nutritionist, a balance and varied diet plan is designed to control the calories, which is individualised depending on the level of obesity, the presence of other diseases, age, the level of physical activity, and the preferences of each person.

  • Reduce the calorie supply. The key to lower weight is to reduce the amount of calories consumed. By means of an interview with a dietician, eating and drinking habits can be reviewed with the aim of estimating the amount and type of calories ingested, as well as to establish specific strategies to reduce them.
  • Choose healthier foods. In order to have a healthier diet pattern, one should increase the consumption of plant products such as greens, vegetables, fruit, whole grain cereals, and pulses. If consuming small amounts of fat, ensure that they are from sources that are healthy for the heart, such as olive oil, dried fruits, and blue fish. The consumption of animal products must be much reduced, giving priority to lean meats such as white fish, white meat, and dairy products with a low fat content. It is advised to limit the consumption of red meats and their derivatives, as well as the addition of salt and sugar.
  • Limit the consumption of high calorie foods. Foods high in saturated fats such as fatty cold meats, pastries, cakes, and pre-cooked foods, cold drinks with sugar, as well as alcoholic ones, are a sure way of consuming more calories, thus to limit them or remove them completely from the diet is advisable in order to begin reducing the consumption of calories.
  • Plan meals. Have three main meals and two snacks a day.
take part in regular physical exercise

Exercise. Physical activity adapted to the possibilities of each individual and practiced regularly contributes to help control weight, to improve the associated risk factors, and positively influences the feeling of well-being. To increase the levels of physical activity it is recommended:

  • To plan the physical exercise. It is recommended to start practicing physical activity for at least 150 minutes per week and to gradually increase its duration, intensity, and variety, so as to improve resistance and physical status. Some recommended activities are, to walk fast, ride a bicycle, to swim, to practice pool gymnastics, or to dance The type of physical exercise can also be varied and perform toning / strength and flexibility / balance exercises.
  • Reduce sedentarism. To be active provides great benefits. It is recommended to walk up the stairs instead of taking the lift, park further away from home, occupy yourself with chores in the home and in the garden, be active in leisure time…

Pharmacological treatment of Obesity

According to the recommendations of the scientific societies, pharmacological treatment is recommended as an adjuvant to the treatment with diet and exercise in individuals with a BMI greater than 30 kg/m2 or 27 kg/m2 with at least one disease associated with obesity (dyslipidaemia, high blood pressure, or fatty liver).

The aim of this treatment is to help in the adherence to the changes in lifestyle and to induce and maintain the weight loss.

The treatment requires a medical indication and supervision. In Spain, the drugs approved for the treatment of obesity are:

  • Orlistat: marketed in 1999. Its main mechanism of action is a reduction, at intestinal level, of 30% of absorption of fat consumed. Its main adverse effects are gastrointestinal such as faecal urgency, flatulence, and smelly faeces.
  • Liraglutide: marketed in 2016. Its main mechanism of action, on being an antagonist of human Glucagon-like Peptide-1 (GLP-1) with a longer half-life compared with that secreted by the body, has anorexigenic effects that help it to regulate the appetite. The main adverse effects are nausea, diarrhoea, constipation, vomiting, decrease in appetite, and a reduction in the blood sugar levels.
  • Bupropion/naltrexone: marketed in 2017. Act on the areas of the brain that control calorie ingestion and balance and reduce the pleasure sensation associated with eating food. When they are given together, they decrease the appetite and the amount of food ingested, at the same time that they increase energy output. The patients that follow this treatment must be subjected to regular monitoring of the response and tolerability of the drug. It must be stopped if there are certain adverse effects, such as an increase in blood pressure or, if after 4 months of treatment, they have not lost at least 5% of their initial body weight.

Surgical treatment of Obesity

Bariatric surgery (BC) is a group of surgical procedures for the treatment of severe obesity. Bariatric surgery is currently the only effective treatment to achieve a significant and sustained weight loss. Bariatric surgery techniques are divided into restrictive techniques, mixed, and malabsorptive techniques, depending on the changes at gastrointestinal tract level and its impact on the nutrition.

Although bariatric techniques continue to advance, in Spain, the most common techniques are currently:

tratamiento quirúrgico estómago gastrectomía tubular

Tubular (or sleeve) gastrectomy (restrictive). Consists of removing approximately 80% of the stomach so that the remaining 20% acquires a tubular shape (resembles a banana). Among the postulated weight loss mechanisms of this technique are: the significant reduction in food ingestion (and, thus, calories) that can be consumed, on reducing the volume (capacity) of the stomach, as well as the effect the surgery has on gastrointestinal hormones that have an impact on a series of factors that include hunger and satiety.

tratamiento quirúrgico obesidad bypass gástrico

Gastric bypass (mixed). Considered the “gold standard” of bariatric surgery. The configuration of this technique is highly effective since it includes a restrictive component with a limitation of oral ingestion, and malabsorptive, with a calorie absorption limitation. Another proposed weight loss mechanism is that, on diverting the passage of food of the proximal portion of the small intestine, changes are produced in the gastrointestinal hormones that promote satiety and hunger.

tratamiento quirúrgico obesidad gastrectomía y bypass

Duodenal switch or biliopancreatic bypass (mixed, but with a predominance of the malabsorptive component). It consists of performing, on the one hand, a sleeve gastrectomy and, on the other, a biliopancreatic bypass by means of which the gastrointestinal secretions are shunted at the end of the small intestine (100 cm), which significantly alters the absorption of foods. On being a more malabsorptive technique, it achieves a greater weight loss compared with the two previous techniques, but it can also have a higher risk of complications like diarrhoea, nutritional deficiencies and protein-calorie malnutrition.

Complications of surgical treatment of Obesity

Bariatric surgery, on being major gastrointestinal surgery, entails the possibility of complications and secondary effects. The complications due to the surgery or surgical comorbidity are around 10%.

Among the early and serious complications are rupture of the stapled line, suture dehiscence, ulcers, bleeding, stenosis of the gastric stoma, and pulmonary thromboembolism.

The long-term complications included nutritional deficiencies, among the most common are, iron deficiency (anaemia), vitamin B12 (pernicious anaemia), calcium, vitamin D (osteoporosis), and proteins, which require oral supplements, or intravenous ones if the oral route fails. Other less frequent complications are diarrhoea, protein-calorie malnutrition, low blood glucose, gallstones, and gastroesophageal reflux disease.

General symptoms are also very common, like the feeling of cold caused by the lower amount of fat covering the body surface. Weakness or tiredness is associated with loss of muscle mass and nutritional deficiencies, as well as hair loss associated with a deficiency of proteins and vitamins.

Finally, the excess of skin and cutaneous flaccidity that appear after the weight loss occasionally requires to be corrected with plastic surgery.

Psychological cognitive-behavioural treatment

Psychological factors contribute to the development and/or maintaining of overweight and obesity. They also make it difficult to start and maintain a weight loss treatment.

On the one hand, some people eat more, and less healthily, when they are in negative emotional states, such as anxiety and sadness. Eating can act as a mechanism to confront certain situations that, although it can initially alleviate negative emotions, it finally ends up being a problem. On the other hand, individuals with obesity have a higher risk of having psychological changes. The most common are depressive, anxiety, and eating disorders, as well as those related to substance use. Furthermore, they tend to suffer difficulties of self-esteem and self-image, and in relationships with others.

Cognitive-behavioural psychotherapy is the most effective. The main purpose of the treatment of obesity is to help in the changing, the acquiring, and maintaining of behaviours that enable an improvement in the psychosocial functioning of the patient, as well as a reduction in weight and maintaining it. To identify these situations, external or internal (mental or emotional) that predispose to eating inadequately and provide the patient with behavioural, emotional, and cognitive strategies that help them to have a healthier relationship with food.

The techniques used in this therapy are conceived for the management of anxiety, the resolving of problems, for controlling stimuli, for self-control, and for cognitive restructuring, among others.

Substantiated information by:

Alba Andreu Martí
Lilliam Flores Meneses
Silvia Cañizares

Published: 17 August 2018
Updated: 17 August 2018


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