It is time to bust the myth of physical inactivity and obesity: you cannot outrun a bad diet
A Malhotra1, T Noakes2, S Phinney3
A recent report from the UK's Academy of Medical Royal Colleges described ‘the miracle cure’ of performing 30 min of moderate exercise, five times a week, as more powerful than many drugs administered for chronic disease prevention and management.1 Regular physical activity reduces the risk of developing cardiovascular disease, type 2 diabetes, dementia and some cancers by at least 30%. However, physical activity does not promote weight loss.
In the past 30 years, as obesity has rocketed, there has been little change in physical activity levels in the Western population.2 This places the blame for our expanding waist lines directly on the type and amount of calories consumed. However, the obesity epidemic represents only the tip of a much larger iceberg of the adverse health consequences of poor diet. According to The Lancet global burden of disease reports, poor diet now generates more disease than physical inactivity, alcohol and smoking combined. Up to 40% of those with a normal body mass index will harbour metabolic abnormalities typically associated with obesity, which include hypertension, dyslipidaemia, non-alcoholic fatty liver disease and cardiovascular disease.3 However, this is little appreciated by scientists, doctors, media writers and policymakers, despite the extensive scientific literature on the vulnerability of all ages and all sizes to lifestyle-related diseases.
Instead, members of the public are drowned by an unhelpful message about maintaining a ‘healthy weight’ through calorie counting, and many still wrongly believe that obesity is entirely due to lack of exercise. This false perception is rooted in the Food Industry's Public Relations machinery, which uses tactics chillingly similar to those of big tobacco. The tobacco industry successfully stalled government intervention for 50 years starting from when the first links between smoking and lung cancer were published. This sabotage was achieved using a ‘corporate playbook’ of denial, doubt and confusing the public.4
Coca Cola, who spent $3.3 billion on advertising in 2013, pushes a message that ‘all calories count’; they associate their products with sport, suggesting it is ok to consume their drinks as long as you exercise. However science tells us this is misleading and wrong. It is where the calories come from that is crucial. Sugar calories promote fat storage and hunger. Fat calories induce fullness or ‘satiation’.
A large econometric analysis of worldwide sugar availability, revealed that for every excess 150 calories of sugar, there was an 11-fold increase in the prevalence of type 2 diabetes, in comparison to an identical 150 calories obtained from fat or protein. And this was independent of the person's weight and physical activity level; this study fulfils the Bradford Hill Criteria for causation.5 A recently published critical review in nutrition concluded that dietary carbohydrate restriction is the single most effective intervention for reducing all the features of the metabolic syndrome and should be the first approach in diabetes management, with benefits occurring even without weight loss.
Full journal article here
