It has been demonstrated that certain energy-related behaviours such as poor or over-nutrition, inactivity, lack of sleep and stress – which are known determinants of metaflammation, as well as obesity – can lead directly to chronic diseases independent of obesity.15,16 The implications are that, although treating obesity should decrease the risk of many adiposity-related conditions (such as diabetes, obstructive sleep apnoea, hypertension and heart disease), effective prevention and management of chronic disease still requires attention to the full range of lifestyle and environmental factors that are determinants of chronic disease – with or without obesity (Figure).17 To address the problem it is important to deal not only with the proximal, or immediate, causes of ill-health, but also with more medial and distal causes (i.e. the ‘cause of the cause’ and the ‘cause of the cause of the cause’).18
Given the need to address the range of lifestyle and environmental factors that determine obesity, the following 10 suggestions are proposed for clinicians to approach weight management in primary care. Due to space limitations, these have not been extensively elaborated. They are intended for consideration for further discussion.
1. Encourage reduced energy intake volume
Despite various theories and claims for the weight-loss benefits of a range of different diets, exercise programs, techniques, tools, etc., there is no evidence that weight loss can occur without a negative energy balance (where energy expenditure exceeds energy intake). There may be individual differences in nutrient storage capacities and energy costs of metabolic processes but, in general, total energy intake can be explained in terms of the total ‘volume’ of food and drink (Box 1).
2. Advocate increased energy expenditure volume
As with energy intake above, there are no substantive data to support different forms of physical activity in weight loss, over and above that provided through an increase in total energy ‘volume’.
Some forms of activity may be more efficient than others in expending energy, such as excess post-exercise oxygen consumption (EPOC) or ‘afterburn’ – this is strenuous activity that leads to a measurably increased rate of oxygen consumption after the activity and sustained calorie burning.19
Still, the general requirement for weight loss is to increase total energy expenditure ‘volume’, i.e. through increasing the frequency, intensity and duration of physical activity (Box 2).
3. Recognise the hierarchy of determinants of obesity (the bigger picture)
Every person is different. It is useful to consider the wide range of possible determinants of disease (Figure) and identify the key factors driving weight gain or inhibiting weight loss in an individual that should be prioritised for intervention.
For example, stress can lead to greater food intake, less physical activity and changes in metabolic rates in one individual but may have the opposite effect in another. Lack of sleep can affect a person’s ability to be physically activity during the day as well as their food intake. All determinants on the pathway need to be considered and not just one end, or even one aspect of one end (e.g. diet or exercise at the proximal end).
This will also require focusing on the patient’s environment, both micro (e.g. home, neighbourhood, school, etc) and macro (e.g. city, country, world, etc),7 to understand the often-unrecognised influences on energy balance and, if possible, act to relieve these or at least acknowledge their influence.
4. Check parental and family weight history and invoke family and/or peer support
Genetic makeup plays a big part in the risk of weight gain and the ease of weight loss. However, this effect is the result of the interaction of numerous genes associated with energy regulation rather than a single gene defect. Thus, although expensive gene sequencing techniques are now becoming more available and affordable, there is no need for these techniques in the clinical situation as the presence of one or both obese parents and obese sibling/s indicates a genetic predisposition and implies an added level of complexity in dealing with the problem. There is a strong interplay between genes and the environment in the development of weight problems. As families share environment as well as genes, it is important to consider problem lifestyle behaviours within a family. (To differentiate this, one of our colleagues suggests asking the patient if their mother, father or siblings are overweight or obese and if the family dog or cat is overweight or obese.)