Obesity and Weight Control: Is There Light at the End of the Tunnel?

Our global population recently arrived at the landmark figure of seven billion, and the nutrition problems we face are increasing as rapidly, with the longstanding crisis of undernutrition joined by the escalating problem of overconsumption and obesity. Over the past 30 years, it has become clear that control of body weight is as simple as matching energy intake to expenditure, yet how to achieve this in the current obesigenic environment is far from simple. A review of causative mechanisms shows controlling eating behaviour and food intake as central to regulation of body weight, but in an environment where the need to suppress intake is uppermost, there are few physiological mechanisms with which to tackle this.

Macronutrient composition, energy density, food format (beverages), palatability, portion size and hedonics all influence intake and readily promote overeating. Currently, the most successful obesity treatment is restrictive bariatric surgery, both invasive and expensive, achieving better outcomes than diet and exercise. Despite considerable advances, there remains a critical gap in translation of underpinning knowledge into successful public health outcomes, as recently outlined in the 2nd Lancet series in obesity with no country reporting decreased obesity prevalence in the last 30 years.

Future contribution may come from better understanding of mechanisms including gut-brain axis and regulation of appetite, the gut microbiome and the genetic underpinning of bodyweight control. Clearly, prevention is the key, with nutrition education required to lead changes in behaviour, and possibly the only viable long-term approach. Whether the global obesity trend can be reversed without significant change in national food policies and/or the built environment however is under debate, and without doubt a major public health challenge for tomorrow if there is to be light at the end of the obesity tunnel.