Education and empathy are needed to fight our obesity epidemic

If you want to know if you are overweight, you need to calculate your body mass index (BMI). This is a measure of your body fat based on your weight relative to your height. It’s your weight in kilograms divided by the square of your height in meters, and if it’s 25 or more, you’re overweight. If your BMI is over 30 then you are obese.

If only we could lose weight, our risk of so many diseases would be greatly reduced. In 2019, the burden of obesity on global health services was estimated at a staggering $2 trillion. And things keep getting worse. A recent detailed study found that the prevalence of obesity has been steadily increasing in 195 countries. Between 1980 and 2015, the number of overweight people in 73 countries doubled.

Last week, the World Health Organization (WHO) informed us that overweight or obesity was at epidemic proportions in Ireland and other European countries. Almost six out of ten adults in Europe are overweight or obese. Among them is every third school child.

Another recent Eurostat study found that Ireland had the second highest obesity rate in the EU in 2019. Only Malta has a higher rate. A quarter of Irish adults are obese; 61pc are overweight or obese. If we look at different regions in Ireland we see that Cavan, Donegal, Leitrim, Louth, Monaghan and Sligo have the most overweight people while those in Galway, Mayo, Roscommon, Cork and Kerry have the lowest proportion.

Why are we in this position? Well, like many other diseases, obesity is the result of an interaction between genetic and environmental factors. Some people have versions of genes that put them at risk of becoming obese. More than 40 genetic variants have been identified, so it’s complex. Some of these genes can double your risk of becoming obese. One study showed that 80 percent of children born to two obese parents were also obese, compared to less than 10 percent of the offspring born to two normal-weight parents.

All the evidence suggests that different people exposed to the same environment have different risks of obesity based on their genetic makeup. If you have the right genes, it looks like you can have your cake and eat it.

what can be done The WHO makes a number of recommendations. They want taxes and restrictions on the sale and marketing of foods that are considered unhealthy. They are calling for subsidies to increase fruit and vegetable consumption and better labeling of the nutritional properties of foods. Better access to open spaces and improved walking and cycling opportunities are also recommended.

What about diets? You may have heard of diets like the Beverly Hills Diet, the Liquid Diet, the Paleo Diet, or the Atkins Diet. Do any of these work?

In 2015, a large study was conducted by Johns Hopkins Medical School in the United States. They looked at 4,200 studies involving 32 diets. Weight Watchers and Jenny Craig diets were the only ones that were scientifically proven to work. One reason is that they also include social support. People need each other in so many ways, even when trying to lose weight.

The issue of fat shaming was highlighted by James Corden on his Late Late Show in the USA. He spoke about the psychological impact of his weight struggle. He said despite trying very hard, he’s never been able to control his weight and said he’s had “good days and bad months”.

He spoke out against another US commentator, Bill Maher, who said fat shaming needs to make a comeback. Corden said this is bullying and the only thing we know about bullying is that it never works, it just makes people feel bad.

A panel of experts agreed, issuing a statement saying that we should all “advance education about weight stigma to enable a new public narrative about obesity.”

How about a medicinal solution? The most effective treatment is what is known as bariatric surgery. It is recommended for people with a BMI of 40 kg/m2 and has been proven to be a life saver. If you are a diabetic who is also obese, it can add nine years to your life. Part of the stomach is removed or bypassed. Various hormones are secreted by the stomach and control the feeling of hunger. Bariatric surgery appears to alter the balance of these hormones and results in weight loss.

Various medications can lead to weight loss. The drugs orlistat and liraglutide can help with weight loss, but they have side effects. Orlistat works by reducing the absorption of fat from your food; Liraglutide allows your body to metabolize sugar and prevent fat storage.

Liraglutide has a curious origin story. A species of lizards called the Gila monster has been found to have a venom that can lower blood sugar when injected into its prey. Since we need sugar for energy, lowering it would weaken the prey. Scientists purified the active ingredient from the poison and showed that it can lower blood sugar in diabetics.

Using the venom as a starting point, liraglutide was made and shown to have the same effects. It has also been shown to suppress appetite and reduce weight by 5 to 10 percent. Then a souped-up version of liraglutide called semaglutide was shown to help people lose about 15 percent of their body weight. Treating obesity is big business. Semaglutide and liraglutide generated sales of more than $1.2 billion in 2021.

Now comes the news of a new drug, tirzepatide. This is also based on liraglutide, but is stronger. People lost up to 24 kg over the course of a 72-week study. On average, there was a 20 percent weight reduction. There were some side effects, including nausea (in 30 percent of people) and diarrhea (20 percent), but these were found tolerable given the notable effect on weight.

The obesity epidemic is increasingly viewed as a medical emergency. We would do well to adopt a multi-pronged strategy to deal with this. It is important to provide support and encourage healthy eating and exercise. But for many who, despite their best efforts, become overweight and obese, medical intervention with anti-obesity therapies offers hope.

Luke O’Neill is Professor of Biochemistry in the Department of Biochemistry and Immunology at Trinity College Dublin