European Associations Review Dietary Therapies for Obesity

Carla Nieto

April 28, 2023

MADRID, Spain — The European Association for the Study of Obesity (EASO) and the European Federation of the Associations of Dietitians (EFAD) have published a position statement to provide an update on evidence-based options for the medical nutrition therapy of obesity. The statement is intended for health professionals and policymakers.

According to its authors, this document mainly responds to the need to confront a problem with "epidemic overtones" that continues to grow across Europe. The prevalence of obesity in adults in the European Union is 23% (2021 data), obesity and overweight together have a prevalence of 60%, and forecasts for 2025 suggest that one in four European adults will live with obesity.

Likewise, as pointed out in the text, European economic studies show that obesity and its complications account for approximately 8% of annual national healthcare budgets.

The document is based on a systematic review of 56 clinical trials and meta-analyses that were published between November 2018 and March 2021. The investigators sought to identify the latest evidence on the different types of medical nutrition therapy available to European obesity specialists.

The results of this analysis demonstrate that while options involving calorie restriction are effective in promoting weight loss, adherence to long-term behavior changes may be better supported through interventions based on eating habits, food quality, and full attention during mealtimes (that is, mindfulness).

The review also confirms that the Mediterranean diet, vegetarian diets, the Dietary Approaches to Stop Hypertension (DASH) diet, the Nordic diet, and low-carbohydrate diets are associated with improved metabolic health, with or without changes in body weight.

Level 1a Evidence

The specialists highlighted that the highest level of scientific evidence (level 1a) relates to the very low-calorie ketogenic diet.

In an interview with Medscape's Spanish edition, Enric Sánchez, MD, a dietitian and nutritionist at Santa María Hospital in Lleida, Spain, and coordinator of the Diet Therapy Working Group of the Spanish Association for the Study of Obesity (SEEDO), said, "This is the first document from a renowned scientific association that includes the very low-calorie ketogenic diet in the recommended treatment for obesity, through which the EASO and the EFAD jointly endorse this treatment with the highest level of scientific evidence. This level is achieved after a systematic review with homogeneity of high-quality studies."

For Sánchez, this recognition suggests that the stigma applied to ketogenic diets in the past (mainly because of their association with greater cardiovascular risk) has been overcome, "and in practice, it implies that dietitians and nutritionists have an additional tool to treat people living with obesity," he stated.

In the same line of thought, Cristina Porca, PhD, co-coordinator of the Diet Therapy Working Group of SEEDO, commented to Medscape's Spanish edition that "compared to the other diets analyzed in the review, the very low-calorie ketogenic diet provides an essential component, because it has the advantage of resulting in significant weight loss, also leading to an improvement in various health markers and comorbidities associated with excess weight, such as hypertension, dyslipidemia, type 2 diabetes, and fatty liver disease."

"Another aspect to take into account is that the weight loss achieved with this type of diet remains stable for a period of up to 2 years, provided that the follow-up and maintenance stages are performed correctly," added Porca. She stressed the importance of good design and structure for very low-calorie ketogenic diets, since the key to obtaining these benefits lies in the continuity of patient adherence to the diet.

"This evidence shows that the very low-calorie ketogenic diet is an effective method in the short and medium terms. Regarding the long term, there is no effective treatment at present, not even bariatric surgery, which is why the creation of chronic drugs for this disease is so necessary, without forgetting that all treatments can be used jointly in support of one another," said Sánchez.

For the experts at SEEDO, an example of the very low-calorie ketogenic diet is the PronoKal method, which is initially based on the consumption of protein-rich foods that promote a state of controlled ketosis. The beneficial effects attributed to the very low-calorie ketogenic diet are obtained mainly during the ketogenic phases of this method. The PronoKal method has the added advantages of applying a standardized protocol, remaining under medical supervision, and combining diet, exercise, and coaching, according to Porca and Sánchez.


The position statement also states that medical nutrition therapy for patients with overweight and obesity must always be administered by trained dietitians who form part of a multidisciplinary team. Its objective must be improved health in addition to changes in weight.

The statement encourages specialists to consider all options within the wide range available in Europe to offer flexible interventions that are as personalized as possible. In this regard, the authors recommend approaches that avoid calorie restriction and detailed eating plans (without falling into the "diet" approach), because they have been shown to improve patient quality of life and body image.

"There are as many motivating factors for losing weight as there are people, and treatment must be individualized in each case and for each moment. It is during the consultation when we find out the most decisive factors for each patient. It can be riding a bicycle, walking the dog or climbing the stairs without getting tired, wearing a certain size of clothing, or looking good in a swimsuit, for example. These factors are usually quite basic, because the quality of life of persons with obesity is severely affected. We have to understand that depending on the level of obesity, many people cannot shower or dress themselves on their own, and many are even unable to go down the stairs to leave the house," said Sánchez.

However, implementing this individualization approach is not always easy. "The main obstacle we face as professionals is time," said Sánchez. "We have just a few minutes to try to get to know the patient, and we need to learn about all their routines, personal values, tastes, hobbies, preferences, social customs, therapeutic objectives, and as much information as possible to be able to act from the root of the problem. It's easy to understand that trying to get to know someone in about 15 minutes is mission impossible. For this reason, until recently, and even still today, general diets were dispensed, given out to all patients equally. For some time, patients would try to adapt to these recommendations, but then they would return to their usual habits and stop treatment. This is why it is essential to adapt the approach to the person, and not the other way around."

BMI and Bias

The evidence collected in the EASO-EFAD review raises questions about BMI as a "reference" measurement. Although it is widely used in population and health economics studies, it is not an accurate tool to identify complications deriving from excess fat that the individual patient may have, according to the authors.

Porca emphasized that the need to complement the measurement of BMI with other parameters is becoming increasingly important. "Perhaps we could say that it is an obsolete measurement, because its importance is centered on weight, and it has been observed that it is not this factor, but rather body composition and functionality that should gain more importance in the diagnosis and management of obesity. However, it is not feasible for all centers to have the necessary equipment to determine these parameters, so the correct thing to do would be to discuss the need to have complementary measurements that provide information besides that derived from BMI."

For Porca, the most appropriate parameters or measurements would be those of body composition using bioelectrical impedance, which allows for differentiation of fat, muscle mass, visceral fat, water, etc. Other important measurements include phase angle, nutritional ultrasound, dynamometry, gait analysis, the timed up-and-go test, and waist and hip circumferences.

The document strongly emphasizes the importance of assessing what the authors call "weight bias" in the management of patients with obesity. This bias refers to professionals' negative attitudes and beliefs about excess weight and about people living with obesity. The review shows that such bias can affect the medical care provided and its quality.

This bias is associated with the stigma and discrimination that overweight and obese people face throughout their lives in various settings. It significantly reduces their quality of life and increases mortality and morbidity, regardless of BMI.

According to EASO and EFAD, to eliminate the impact of this bias requires a focus not only on weight loss, but also on improving patient health and well-being. The objective of the treatment is to achieve a broad spectrum of positive health outcomes.

"If we only look at weight, we are showing a huge bias. In these interventions, what interests us is to focus the working point on the kilograms of fat, specifically on the loss of that fat, and on the maintenance of muscle mass. In this way, the objective can be correctly focused on," said Porca.

Sánchez and Porca report no relevant financial relationships.

Follow Carla Nieto of Medscape's Spanish edition on Twitter @carlanmartinez and on LinkedIn.

This article was translated from Medscape's Spanish edition.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.