Can you really be fit but fat? What ‘healthy obesity’ really means according to the experts

Sashaying down the catwalk in stratospheric heels for Dolce and Gabbana last month, supermodel Ashley Graham was a picture of health. Her skin glowed and her thick hair tumbled around her chiselled jawline. Unsurprisingly for a catwalk model, her Instagram account shows her working out in the gym, deadlifting or doing yoga.

“I’m always at the gym,” she told one interviewer. “I probably go five times a week. However, Graham isn’t your run-of-the-mill skinny model. With a rumoured BMI of over 29, the 35-year-old mother-of-three and body-positive activist is hovering on the cusp of obesity – which starts at a BMI of 30.

But can Graham really be as healthy on the inside as she appears? After all, we are constantly warned of the risks of piling on the pounds. A study of more than 11,000 adults found that people who were overweight or obese were twice as likely to have conditions including high blood pressure, diabetes and osteoarthritis.

However, a new term emerged from a medical conference this week: “metabolically healthy obesity”. According to the latest research presented at the annual meeting of the European Association for the Study of Diabetes, 15-20 per cent of people living with obesity have none of the complications associated with the condition, namely abnormal blood sugar control and blood fats, high blood pressure, type 2 diabetes and other signs of cardiovascular disease. The study looked at people aged 40 to 60 and found one in four women were “healthily obese” compared to between 2 and 19 per cent of men.

This may be good news for those of us who were looking forward to baggy jumper season. But why do some people tend to be healthy and fat while others suffer serious health consequences?

The answer, says Dr Giles Yeo, a neuroscientist at the University of Cambridge and author of the book Why Calories Don’t Count: How We Got the Science of Weight Loss Wrong, lies in our genetics and hormones. “People think you lose and gain fat cells when you lose or gain weight,” he says, “but fat cells that sit just under the skin act like balloons, filling with fat and increasing with size as you gain weight.”

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Fat tucked away like this is relatively safe, but the amount of storage space in our cells can vary hugely from person to person. And, says Dr Yeo, once those cells are full, fat can spill into organs and muscles and cause metabolic mayhem. “The moment we exceed our genetically determined capacity, we will get ill,” he says. “That’s why some larger people will never get diabetes, while some skinny people will.”

When it comes to body fat, location matters almost as much as quantity. This explains why women are less at risk. Dr Sarah Berry is an associate professor in nutritional sciences at Kings College London and the lead nutritional scientist on the Zoe Predict programme, which studies the role of food in health.

“Visceral fat in the upper body – the kind that causes a ‘beer belly’ or apple shape – is ‘metabolically active’,” she says, “which means it upregulates the production of chemicals that affect chronic diseases such as inflammation and type 2 diabetes. In contrast, fat on the thighs and hips is less metabolically active and more benign.”

Body shape is driven by genetics and hormones, Dr Berry says, and “male fat is more concentrated on the abdominal area while female fat tends to be laid down on the hips and thighs”.

As a result, a man will have more visceral fat than a woman even if they have the same BMI, which is why Roy Taylor, professor of medicine and metabolism at Newcastle University, says that “men develop type 2 diabetes at a lower BMI than do women”.

However, at menopause, things can go haywire. Surprisingly, studies have recently shown that our metabolisms only start to slow down when we reach 60. But many women will complain of mid-life spread long before this. In an Australian five-year study of women aged 46 to 57 (published in the journal Climacteric in 1999), menopause appeared to trigger an increase in abdominal, or visceral, fat.

“At menopause,” Dr Yeo explains, “oestrogen levels plummet. Women now have a higher ratio of testosterone to oestrogen, which makes their bodies more hormonally ‘male’. This leads to gaining weight around the waist and the typical body shape changes around the time of menopause. Broadly speaking,” he says, “if your waist circumference is more than your hips, you are at higher risk of metabolic disease, regardless of your sex.”

Can you reduce that risk? Yes, says Dr Yeo. “Exercise plays a big role in health even if it doesn’t change your weight one gram,” he explains. “If you are carrying muscle, you will always be healthier than someone at the same weight with less muscle.”

But the good news is visceral fat is easier to eliminate with exercise than other types.  A 2013 review from the University of Antwerp reported that strength training and aerobic exercise were equally effective in whittling waists, even when people didn’t lose weight per se. It suggested people aim for at least ‘moderate to vigorous’ intensity exercise for best results, which is anything that makes you warm and sufficiently breathless that you can talk but not sing.

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Want more inspiration? In 2012, an extensive review reported that fit overweight and obese people were up to 60 per cent less likely to die early than unfit people with a normal BMI. “These findings suggest that it is more beneficial to be fit and overweight or obese rather than normal weight and unfit,” the researchers stated. The study didn’t recommend a particular type of fitness plan. However, it suggested that people should aim to burn at least a thousand calories a week via exercise “for a significant reduction in mortality risk”.

But this doesn’t mean that you don’t need to worry about losing weight if you are heavy but put the hours in at the gym At the diabetes conference, Prof Matthias Blüher from the University of Leipzig and Helmholtz Centre, in Munich, pointed to previous work that suggests people who are “healthy obese” still have a higher risk of coronary heart disease, cerebrovascular disease and heart failure than their counterparts in a normal weight range.

Other experts concur. While exercise is always a good thing, Prof Taylor says, “weight is still the most important factor for developing type 2 diabetes”. His research has shown that losing around two stone can reverse the condition in many people. Other risks associated with obesity include acid reflux, sleep apnoea, arthritis of the knees and hips, and there may even be an increased risk of some types of cancer.

Plus, says Dr Yeo, the people in the study were comparatively young. “There is an argument that even if you are well now, what are the longer-term consequences of carrying additional fat? Your genetic hand of cards may mean you can be larger and healthier, but that doesn’t mean losing a few pounds might not be beneficial. On the other hand, some people are designed to be heavier, and that’s life.”

And while we can’t all be catwalk models, if you eat healthily, are active, can walk upstairs without getting out of breath, and pick up and play with your children and grandchildren despite having an overweight BMI, then being healthier might not necessarily involve being lighter. As Dr Yeo concludes: “A healthy weight for you takes care of itself.”