Lose weight without dieting

Some people can eat what they want and stay slim, others gain weight. What are the causes of obesity? What is the most promising way to reduce and maintain body weight? Professor Dr. Christina Holzapfel has recently been appointed Professor of Human Nutrition at Fulda University of Applied Sciences and conducts research primarily on obesity and weight reduction. In an interview, the nutritionist explains what personalised nutrition can achieve and what role apps play in weight reduction.

Professor Holzapfel, what would you advise a person who wants to reduce their weight?

I recommend changing your diet in the long term and increasing your physical activity. Diet is about eating fewer calories. The easiest way is to replace high-energy foods with lower-energy alternatives, for example jacket potatoes instead of chips, ham instead of salami, plait instead of cake, schnitzel au naturel instead of breaded schnitzel. In this way, calories can be saved while maintaining the same level of satiety. I advise against short-term diets. For weight reduction, you should save about 500 kilocalories a day. The dietary recommendations of the German Nutrition Society (DGE) e.V. are a good guide to eating a plant-based and calorie-conscious diet. It is also important that people do not go hungry. In addition, the food must be tasty in order to be able to maintain the lower-energy food choices in the long term. This is because only a long-term balanced and energy-reduced diet will lead to weight reduction and maintenance.

The DGE is currently revising its dietary recommendations. The aim is to make them more true-to-life and thus more practicable. What exactly will change?

The DGE will soon publish food-related dietary recommendations. For this purpose, an algorithm has been specially developed that evaluates food according to various criteria such as health, environment and social issues; among other things, the topics of sustainability and animal welfare also play a role. The recommendations for nutrient intake, including calorie intake, will not change. Details on the new recommendations are not yet known.

When it comes to obesity, we are talking about a disease that greatly increases the risk of diabetes, cardiovascular diseases and various types of cancer. What does obesity therapy currently look like in Germany?

In principle, there are various options for obesity therapy. The basis for every therapy measure is the so-called multimodal basic therapy with the building blocks of diet, exercise and behaviour. Other approaches include formula diets, i.e. protein diets or medication, or surgical interventions. Depending on the amount of body weight, those affected decide together with experts which approaches make sense. However, when it comes to payment, the costs are covered on a case-by-case basis or the health insurance companies only subsidise the therapy. Only the costs for certain apps, so-called digital health applications, abbreviated DiGAs, which meet certain criteria, are currently fully covered by the health insurance funds. Overall, the care situation for people with obesity in Germany is deficient and urgently needs to be improved.

What can digital health apps (DiGAs) do with regard to weight reduction? And is personal nutrition counselling still needed?

For weight reduction, there are currently two approved DiGAs that meet the relevant criteria: Zanadio and Oviva Direct for obesity. Both apps lead to moderate weight loss, as expected. These apps can be prescribed by doctors. The health insurance company then provides a free code to activate the app. Certainly, apps are not equally suitable for all people, which is why I recommend additional nutritional counselling with a qualified nutritionist.

They work to improve obesity treatment. Among other things, you are trying to identify factors that are associated with successful weight management. What factors are you looking at closely? And what firm findings do you already have?

In my research work, I am investigating the effect of different approaches to weight reduction. I am particularly interested in genetic factors. We know that body weight has a genetic component. Our evolutionarily stingy genetics meet a cornucopia of energy-rich foods, which favours overweight and obesity. Currently, however, this knowledge of genetics has no practical relevance, which means that genetic information is not currently taken into account in obesity therapy. Nutrition recommendations based on genes are offered for a lot of money, but there is no scientific knowledge behind them. The knowledge on personalised nutrition and its practical implementation is limited, which is why there is currently a lot of discussion and research on the topic of personalised nutrition.

The desire for personalised nutrition is obviously great. What is meant by this?

Personalised nutrition involves a dietary recommendation or product that is tailored to the needs and requirements of the individual person. This tailored nutrition can incorporate different information such as genetics, blood parameters, lifestyle, stress, sleep or health status. Nutritionists already take such aspects into account when providing nutritional advice. It is exciting to see how digital tools and artificial intelligence methods will use this data for personalised nutritional advice in the future.

One more question appropriate to the time of year. In spring, many people go on fasting diets. Is this a way to lose weight?

Fasting cures are not suitable for permanent body weight loss. However, they can be an introduction to a healthier diet, which can be associated with weight loss if calories are saved.

Personal details
Dr. Christina Holzapfel (40) took up the professorship for Human Nutrition at the University of Applied Sciences in Fulda on 1 November 2022. The nutritionist also heads the research group "Personalised Nutrition & eHealth" at the Technical University of Munich. In her research work, she is primarily concerned with the topic of obesity and weight reduction. She uses various methods to investigate which parameters are associated with successful weight management. She is active as an expert in many committees and has published numerous manuscripts in international journals.

Obesity
More than 50 percent of adults in Germany are overweight. Overweight is defined as having a Body Mass Index (BMI) of 25 kg/m² or more. Obesity is defined as a BMI of 30 kg/m² or more. It is well known that the development of obesity is complex and that a positive energy balance leads to an increase in body weight. This means that the body takes in more energy than it consumes.
The Corona pandemic has exacerbated the obesity situation in Germany. According to a survey, 40 percent of respondents gained about 5.5 kg during the pandemic. Overweight and obesity are the trigger for many diseases such as diabetes, cardiovascular diseases as well as various cancers.

This is how the Body Mass Index (BMI) can be calculated:
The height in metres and the body weight in kilograms squared are needed. The BMI is obtained by dividing the body weight in kilograms by the body height in metres squared.
Example for a person with a body weight of 85 kilograms and a height of 1.70 metres: 85 kg / (1.7 m)² = 29.4 kg/m². The person is overweight.