Combating the obesity epidemic is one of the greatest challenges of modern times. Although diets for weight loss have been around for more than 2,500 years, they have obviously not been particularly successful, as rates of overweight and obesity have continued to increase across the world over the past several decades. According to the World Health Organization (2016), Europe falls in the second place globally with more than 80% of the adult population struggling with excess body weight. Poor diet, both in quantity and quality, and a physically inactive lifestyle are characteristics of modern obesogenic environments and can trigger weight gain in susceptible individuals and thereby increase risk for noncommunicable diseases such as type 2 diabetes, metabolic syndrome, and coronary heart disease.
The balance between energy intake (calories from the food we eat) and energy expenditure (calories we burn for survival and all activities of daily living) is critical for body weight homeostasis. When energy intake exceeds energy expenditure for prolonged periods of time, the excess calories are stored in the body, mostly as fat. It appears thus straightforward that increasing energy expenditure (e.g. by exercising more) and decreasing energy intake (e.g. by eating less calorie-dense foods) would suffice to manage overweight and obesity. Although in theory this sounds plausible, real-life application has proven that treatment of obesity is far more complicated than a simple exercise of measuring calories in and calories out. Obesity is a multifactorial disease and should be tackled as such.
Scientists have long debated on the optimal diet for weight loss in terms of macronutrient composition, i.e. whether it should be high-fat, low-carbohydrate or high-protein. Accordingly, a wide range of popular diets have emerged over the years and have been proposed to promote superior weight loss, including but not limited to, ketogenic, Atkins, low-carb, vegan, the zone—you name it!
For the most part, all of these diets work in the short-term, with somewhat varying success, but they often fail at keeping off the lost weight in the long-term. Regardless of the diet however, a recurrent observation is that in response to the same dietary treatment, different individuals respond quite differently in terms of weight loss. Some lose considerable amounts of weight, most lose moderate or low amounts of weight, and there are also some that do not lose or even gain weight! This pattern repeats itself for almost any type of diet. In other words, any diet can produce optimal weight loss in some individuals, but certainly not all. This means that there are characteristics – whether genetic or inherent – that make some of us responsive to one type of diet but not others. This can be explained by several factors including genetic variants and how our bodies metabolize food.
In light of this, tweaking dietary treatment plans based on individual metabolic profile can offer great potential in the treatment of obesity, rather than merely depending on general dietary guidelines for everyone. Simply speaking, there is no such thing as a perfect, “one-size-fits-all” diet. The concept of individualisation has been highlighted by Garrod for over a century in his paper on “biochemical individuality” (1902): “…just as no two individuals of a species are absolutely identical in bodily structure, neither are their chemical processes carried out on exactly the same lines”.
There is no optimal diet for weight management that is suitable for everyone, as each person is biochemically unique. Biomarker-based approaches that reflect individual health status and nutrient metabolism can be used to tailor dietary advice for regulating body weight, optimising health and overall well-being.
Revolutionary omics technologies have helped understand how our bodies absorb and utilise nutrients at the molecular level and, therefore, how different individuals differ in these biochemical processes. Our metabolism is also partly influenced by some of our “guests” – namely the bacteria in our gut (the so-called “gut microbiome”) – which contribute to individual differences in the metabolic effects of the food we eat by producing several microbial metabolites.
In PREVENTOMICS, we have developed a direct-to-consumer platform on the basis of integrating genetic, nutritional, biochemical and behavioural factors to assess the unique metabolic profile of individuals using metabolomics and machine-learning techniques, aimed at delivering personalised nutritional plans to ultimately drive sustainable behaviour change to tackle obesity and thereby, prevent nutrition-related chronic diseases.
The Danish part of the project consists of a dietary randomised controlled intervention trial conducted at the Department of Nutrition, Exercise and Sports (NEXS) at the University of Copenhagen. We are investigating the potential advantages of delivering personalised dietary meals by the company Simple Feast, together with an individually-tailored behavioural change program through mobile app push notifications to men and women aged 18-65 years with excess body weight for a period of 10 weeks.
At the Department of Nutrition, Exercise and Sports (NEXS) of the University of Copenhagen we are investigating the potential advantages of delivering personalised dietary meals to men and women with excess body weight
The meals from Simple Feast include breakfasts and dinners and are delivered twice a week to the participants. Other meals not provided (i.e. lunches and snacks) are presented as recipes through the Simple Feast App, which are designed to match the individual nutritional recommendations for each participant.
Participants who are randomised to the control group receive generic dietary meals and a generic behaviour change program (i.e. not tailored to their individual metabolic profile) according to national guidelines for healthy weight.
Enrolled subjects attend NEXS’ facilities before and after the intervention to measure body weight, body fat, lipid profile, blood glucose and blood pressure, amongst other indicators, for assessing changes in various biomarkers of health and disease. The primary outcome of the study is the change in total body fat mass measured by using dual-energy X-ray absorptiometry.
We anticipate that participants who receive the personalised dietary treatment will experience greater loss of body weight and body fat whilst improving their overall health compared to participants who receive the general dietary recommendations.
The study has just been completed and the Danish team is excited to crunch some numbers and share the results with the scientific community and the public in the near future!
About the author
The University of Copenhagen (UCPH) contributes to the project through the Department of Nutrition, Exercise and Sports (Faculty of Science). The Danish team conducts physiological and clinical research into diet and exercise in the management of obesity throughout the life course.
Mona Adnan Aldubayan
PhD student in Personalized Nutrition at the Department of Nutrition, Exercise and Sports at the University of Copenhagen. Mona has a background in Clinical Nutrition and her PhD research focuses on identification of “metabotypes” based on metabolome and microbiome biomarkers to guide personalized dietary interventions in the management of obesity.
MSc. Kristina Pigsborg is a second year PhD student at the Department of Nutrition Exercise and Sports at the University of Copenhagen. In her PhD-project she is working with personalized dietary management of human health and aiming on identifying new as well as validate newly discovered biomarkers that modify the relationship between dietary intake and overweight/obesity as well as glucose homeostasis.