Lifestyle intervention can be useful across all the spectrum of NAFLD patients. Losing weight decreases cardiovascular / diabetes risk and also regresses liver disease. Weight reductions of ≥ 10% are required for inducing near universal NASH resolution or fibrosis improvement by at least one stage. However, modest weight losses (>5%) also produce important benefits on NAS and its components. In addition, to improve the success of this intervention we need to explore, beyond total calories and type of weight loss diet, the role of micro and macronutrients, evidence-based benefits of physical activity and exercise and finally supporting these modifications through established behaviour change models and techniques.

The Mediterranean diet can reduce liver fat even without weight loss and is the most recommended dietary pattern in NAFLD. The Mediterranean diet is characterized by reduced carbohydrates intake, especially sugars and refined carbohydrates (40% of the calories vs. 50-60% in a typical low fat diet), and increased monounsaturated and omega-3 fatty acids intake (40% of the calories as fat vs. up-to 30% in a typical low fat diet).

Both TV sitting (a reliable marker of overall sedentary behaviour) and physical activity are associated with cardio-metabolic health, NAFLD and overall mortality.

A 'triple hit behavioural phenotype' of 1) sedentary behaviour, 2) low physical activity, and 3) poor diet have been defined. Clinical evidence strongly supports the role of lifestyle modification as a primary therapy for the management of NAFLD and NASH, and this should be accompanied by the implementation of strategies to avoid relapse and weight regain.