The global fight against obesity represents an important new investment theme, according to a new report from a BofA Merrill Lynch research team.

In a new report, the firm’s ESG (Environment, Social, and Governance) and Sustainability team argues that efforts to tackle obesity will form a “mega trend” with significance for the next 25 to 50 years. It singles out stocks in four sectors that may benefit: pharmaceuticals and healthcare; food; commercial weight loss and nutrition; and sports apparel and equipment.

“Global obesity is a mega-investment theme for the next 25 years and beyond. Obesity may be the most pressing health challenge facing the world today and efforts to tackle it will shape thinking by policy makers and in boardrooms around the world,” said Sarbjit Nahal, equity strategist at BofA Merrill Lynch Global Research.

The firm notes that 500 million people worldwide are obese, and 1.4 billion are overweight; and, that obesity is now the fifth leading cause of death, leading to 2.8 million fatalities each year. And, the problem is growing as diets around the world come to resemble those of the West, it says.

The report also says that the costs of managing obesity are much greater than previously believed too, and it expects this to lead to increased government action.

“As happened with smoking, it is likely that the growing cost burden of obesity on governments, corporates and wider society will spur collective action and greater regulation,” it suggests, adding that it expects widespread scrutiny of the causes of obesity such as food and drink, schools, work environments, and sedentary lifestyles.

From an investors’ perspective, it says they should, “take a long term view and a broad perspective in selecting stocks as part of the globesity theme”.

On the pharmaceutical front, it highlights companies that are taking advantage of increased support for obesity drug development from US regulators. “The [U.S. Food and Drug Administration] has historically had little risk tolerance for weight loss drugs, but recently has shown increased support for their development,” said Steve Byrne, biotechnology analyst at BofA Merrill Lynch Global Research.

It also points to companies tackling related medical conditions and needs including diabetes, kidney failure, hip and knee implants, and it considers equipment such as patient lifts, bigger beds and wider ambulance doors.

In terms of food companies, the report looks at how successfully companies are entering the “health and wellness” market, and how they may be impacted by measures such as “fat taxes”. As for sports apparel and equipment, Merrill sees that as a “longer-term play”, but notes that promoting physical activity will become a key priority for more government health policies.