Why obesity is rising and how we can live healthy lives

The word malnutrition is most often associated with people who are underweight through hunger. But it equally applies to people who are obese.

Together, underweight and obesity are known as the ‘double burden’ of malnutrition – and globally, there are now more people who are obese than underweight.

In fact, more than 1 billion people are now living with obesity, according to recent research in The Lancet, which equates to one in eight.

The study used data from 197 countries, covering more than 99% of the world's population, to examine global shifts in underweight and obesity between 1990 and 2022, "a period of substantial change in food and nutrition".

It found that, over the three decades, the prevalence of obesity has more than doubled in adults and quadrupled in adolescents aged between 5 and 19.

The only region where more people are underweight than obese is Southeast Asia, while the highest combined rates of underweight and obesity in 2022 were island nations in the Pacific and the Caribbean and countries in the Middle East and North Africa.

Obesity is more prevalent in women than in men, the study found. Meanwhile, separate studies have found that not only is there an obesity pay gap, but that there's an obesity gender pay gap, with women being paid less than men.

As Dr Tedros Adhanom Ghebreyesus, the Director-General of the World Health Organization (WHO) said, the study highlights the “importance of preventing and managing obesity from early life to adulthood, through diet, physical activity, and adequate care, as needed”.

Zero Hunger is the second of the 17 UN Sustainable Development Goals, but the targets specify “ending all forms of malnutrition” by 2030, including obesity.

The WHO defines obesity and overweight as “abnormal or excessive fat accumulation that presents a risk to health”. It is both complex and multifaceted, caused by the interaction between biological, genetic, social, psychological and environmental factors. A common misconception is that obesity is a result simply of diet and exercise.

It’s thought that, in 2019, around 5 million deaths from non-communicable diseases (NCDs) were caused by being above the optimal BMI or Body Mass Index – a measure that looks at your height and weight to work out if you’re a healthy weight.

NCDs, which include cardiometabolic diseases (such as high blood pressure and diabetes) and cancer, are responsible for around three-quarters of all deaths.

Obesity is in fact linked with more than 200 comorbidities (when people live with more than one disease at a time), according to the American Medical Association, including heart disease and multiple types of cancer.

Studies on the ‘paradoxical state of malnutrition’ in obesity have found that obese people are lacking in essential nutrients more than people with a healthy body weight.

Malnutrition occurs when the body doesn’t get enough or is unable to absorb nutrients, which can have a negative effect on physical performance, cognitive functioning, and well-being.

The rise in obesity is due to a combination of economics and technology that has altered global food systems and consumption patterns.

The Lancet study finds that in the decades leading up to the COVID-19 pandemic, higher incomes around the world enabled people to spend more on food. At the same time, food systems shifted away from subsistence and local farming to an emphasis on transported commercial products.

Simply put, what we consume has changed. People in low- and middle-income countries are largely able to eat more calories, more animal products, and more sugar.

Meanwhile, food processing technology and the “industrialization of food” has meant we’re consuming more ultra-processed foods (UPFs), which lead to “higher caloric intake and weight gain than fibre-rich foods such as whole grains and fruits”.

In the US, for example, UPFs account for 58% of an adult’s diet, according to the British Medical Journal.

These foods are high in salt, sugar, additives and preservatives are designed to be cheap and convenient.

“Both poverty and the cost of food, especially nutrient-rich foods, have increased since the COVID-19 pandemic and the war in Ukraine,” says the Lancet study.

“Together with the adverse impact of climate change on food production and supply, these factors risk worsening both underweight and obesity through a combination of underconsumption in some countries and households, and a switch to less healthy foods in others.”

At the same time, there has been a drop in adult energy expenditure, possibly due to shifts in work and transport, which may have contributed to the rise in obesity.

“There is an urgent need for obesity prevention, supporting weight loss and reducing disease risk in those with obesity,” the authors of The Lancet study said.

“Prevention and management are especially important because the age of onset of obesity has decreased, which increases the duration of exposure.”

Commenting on the study, the WHO’s Dr Tedros said meeting the global targets for curbing obesity would require “the work of governments and communities, supported by evidence-based policies from WHO and national public health agencies.

“Importantly, it requires the cooperation of the private sector, which must be accountable for the health impacts of their products.”

At the World Economic Forum Annual Meeting in Davos in January 2024, experts came together to discuss Fighting the Obesity Epidemic.

Nancy Brown, CEO of the American Heart Association, joined Glen Tullman, Founder and CEO of Transcarent, Shamsheer Vayalil, Founder and Chairman of Burjeel Holdings Plc, and Mads Krogsgaard Thomsen, CEO of Novo Nordisk Foundation, to discuss how societies and health systems can better prepare for and respond to the challenge.

Foreshadowing Dr Tedros' comments, the panellists said addressing obesity was a whole-of-society and systems issue – requiring multi-stakeholder action.

They stressed the urgency of early intervention, beginning with education and awareness at the youngest levels of society alongside parents and families.

Solutions included the impact of food labelling, exercise, and creating access to healthy food.

"The largest amount of sodium is consumed in bread, but most consumers don't understand that," explained Brown.

She said integrating the prescribing of healthy food into the healthcare system could dramatically improve health outcomes in the US.

But healthy food and active lifestyles are “not accessible or affordable for people with low income and autonomy”, the study authors point out.

“Unaffordability and inaccessibility of healthy foods and opportunities for play and sports leads to inequalities in obesity, and could limit the impact of policies that target unhealthy foods.”

As it concludes: “There is an urgent need for programmes that enhance healthy nutrition, such as targeted cash transfers, food assistance as subsidies or vouchers for healthy foods, free healthy school meals, and primary care-based nutritional interventions.”

It's clear to me that, in dealing with obesity, we need to look at the wider healthcare picture and prioritize three key areas:

Businesses also have a role to play. The World Economic Forum's Healthy Workforces initiative is a multi-stakeholder collaboration focused on leveraging the workplace setting to promote the holistic well-being of employees, their families and society at large.

A vital part of this initiative is our work on Healthy Weight and Metabolisms, which focuses on increasing awareness, sharing best practices and supporting a whole-of-society approach to addressing obesity.