We argue that the reason so little progress has been made against obesity and type 2 diabetes is because the field has been laboring, quite literally, in the sense intended by philosopher of science Thomas Kuhn, under the wrong paradigm. This energy-in-energy-out conception of weight regulation, we argue, is fatally, tragically flawed: Obesity is not an energy balance disorder, but a hormonal or constitutional disorder, a dysregulation of fat storage and metabolism, a disorder of fuel-partitioning. Because these hormonal responses are dominated by the insulin signaling system, which in turn responds primarily (although not entirely) to the carbohydrate content of the diet, this thinking is now known as the carbohydrate-insulin model. Its implications are simple and profound: People don’t get fat because they eat too much, consuming more calories than they expend, but because the carbohydrates in their diets — both the quantity of carbohydrates and their quality — establish a hormonal milieu that fosters the accumulation of excess fat.

We fall off track because a part of us isn’t sure that the goal we’re working toward is going to make our lives better. This causes inner conflict, and when there’s inner conflict, we do the easiest thing of all: nothing. I’ve presented this simple worksheet to many clients, and I’ve found that it helps determine what’s really holding them back.

The evidence shows that this kind of behaviour change needs to happen collectively, not just individually. So we need joined-up governance at local, national and international levels. Food systems also contribute significantly to greenhouse gas emissions. This can be addressed by reducing waste or directing it back into the supply chain. A mix of different measures will be most effective. The evidence shows that taxation is one of the most effective ways to modify behaviour. Accreditation and labelling schemes can also have an impact.

Discarding classical solutions such as information campaigns, it offers a much simpler alternative: make the healthy options more tempting. How? By changing their names. Several research teams in the US have tried this strategy in various school canteens and they found that making the names “seductive”, catchy or funny can induce children to eat healthier.

In this randomized clinical trial of 602 overweight and obese adults from 40 states across the United States, gamification interventions with support, collaboration, and competition significantly increased physical activity compared with the control group during the 24-week intervention. The competition arm had the greatest increase in physical activity from baseline during the intervention; during the 12-week follow-up, physical activity was lower in all arms, but remained significantly greater in the competition arm than in the control arm.

In a meta-analysis of real-life experiments drawn from food science, nutrition, health economics, marketing and psychology, the authors find that behavioural nudges - facilitating action rather than providing knowledge or inducing feelings - can reduce daily energy intake by up to 209 kcal, the same number of calories as in 21 cubes of sugar.

“Tracking your daily activity with a pedometer, wearable, or smartphone is an important part of any physical activity program,” Patel said by email. “However, it should be combined with other behavior change strategies such as goal-setting, coaching, or social interventions to increase sustainability.”

If you want a child to eat more vegetables, it might help to use plates illustrated with pictures of vegetables.

Gamification offers advantages over other types of physical activity campaigns due to its ability to bypass the perceived barriers to becoming active. Gamified design can deliver health through stealth by encouraging people to play a fun, free game rather than take part in a fitness scheme.

Strategies for Enhancing Health in the Built Environment