Why Everything You’ve Been Told About Weight May Be Wrong

Low-fat, low-carb, paleo, keto, intermittent fasting – the list goes on. Given that our culture idealises thinness and shuns larger bodies, it’s not surprising that nearly one in five midlife women has dieted in the past few years, according to research. And many have regained the weight and see themselves as having failed. Less than one per cent of very large people got to a ‘normal’ weight at all in a study that included almost 100,000 women, and most who did, regained the kilos they’d lost within five years.

Some medical experts are now saying what many people have been desperate to hear: It’s extremely tough to drop weight long term, for reasons that have nothing to do with willpower – and it may not even be necessary. “The dominant message people get from government, health organisations and the media is that weight and health are connected,” says Dr Jeffrey Hunger, a longtime weight-stigma researcher (and, yes, that’s his real name!). “But, really, there’s no strong evidence to suggest higher weight automatically leads to poorer health.”

If you’re extremely large-bodied, dropping some kilos can protect your joints from arthritis and make it easier to exercise. But, for most women over the ‘ideal’ weight, focusing on other health measures may be much more important than what the scale says. So why isn’t that a message you’re likely to hear? “The evidence has been piling up for years, but experts are so stuck in their beliefs, they don’t accept anything to the contrary,” Dr Hunger says. Add to this all the people and companies with financial interests in pumping out anti-fat messages, from diet purveyors to pharmaceutical companies to book authors. Plus, the message that body fat is bad is such gospel in our society that it’s hard to believe it may not be true.

Weight is not an accurate measure of health

Doctors often worry that heavy women are 'cardiometabolically unhealthy', a term that encompasses blood pressure, cholesterol levels, triglycerides, blood glucose and other measures of heart and arterial fitness. But researchers in the US evaluated more than 20 studies and concluded that there was “no clear relationship between weight loss and health outcomes”. In other words, shedding kilos didn’t meaningfully lower blood pressure, diabetes risk or cholesterol.

Equating being heavier with having poor cardiometabolic health and being thin with the opposite is way off the mark, researchers discovered. They pored over data from more than 40,000 participants in a survey and found that nearly half the people classified as ‘overweight’ (and more than a quarter labelled ‘obese’) had perfectly healthy blood levels of lipids and glucose, meaning they were cardiometabolically fine. Meanwhile, a full 30 per cent of the ‘normal-weight’ participants had unhealthy levels of these markers. The bottom line? Weight alone is not indicative of health, so nobody can tell whether or not a person is healthy based on their weight.

You can be fat and also fit

Our culture equates carrying extra body fat with being out of shape, but plenty of large-bodied women can run laps around their thinner counterparts. That’s because, in reality, fitness and weight have little to do with each other, says Dr Himmelstein. A team of international researchers proved this when they followed 43,000 participants across the weight spectrum. At the outset, they measured blood pressure, cholesterol, glucose and the like, then tested the participants’ fitness levels using a treadmill. Those who were metabolically sound and also fit had the same mortality rates during the next decade regardless of their weight. Those who were considered obese and unfit, however, were more likely to die.

You can actually be too thin

There may be no upper limit to how rich you’d like to be, but there’s definitely a limitation for thinness. Having a body mass index (BMI) below 23 (less than about 55 kilos for a 160cm woman) is linked to greater mortality than being a few kilos heavier, a team of researchers discovered when they examined hundreds of studies with more than 30 million participants. This was true even when they excluded people who might’ve been thin because they were already sick. Plus, sinking to a too-low BMI can make you feel awful. (It’s important to note that BMI has been criticised as a flawed measurement, in part because it doesn’t differentiate between fat and muscle, categorising people with a lot of muscle as ‘overweight’, and it doesn’t consider ethnic differences in body type.)

Weight is more complex than 'kilojoules in, kilojoules out'

"So many things go into the weight you are", Dr Himmelstein says. Genes, ethnicity, medicines you take, where you live, your income and how much sleep all play a role, even if most doctors focus only on kilojoules. Weight is so complex that even longtime researchers don't yet understand all the variables involved. People might be heavier because food is so easily available. Or maybe it's the larger dinner plates and portions we serve compared with 30 years ago. In the US, Dr Barbara Corkey, who specialises in obesity research, is intrigued by the notion that chemicals used in farming, additives in processed foods and/or other toxins that make their way onto your plate may cause your body to erroneously release too much insulin, a hormone that makes you want to eat more. Dr Corkey suggests that it may not be that obesity brings on problems like insulin resistance, but that unnaturally high insulin levels lead to obesity and insulin resistance.

Healthy eating gets you further than a 'diet'

Dieting can help you trim kilos, but keeping them off is another story. The low nutrition levels and excessive exercise of many weight loss plans aren't sustainable, says Dr Hunger. Plus, when you cut back on kilojoules, your metabolism slows to a crawl. "Your body's biological architecture doesn't understand what the thin ideal is - it's doing all it can to protect you from what is perceives as famine," he notes.

The answer? Cardiologist Dr Ruwanthi titans says: "Rather than make a drastic temporary chance for a short-tom goal, focus on small, sustained changes, such as eating more plant-based foods and less red meat and processed fare". Even thin people benefit from ditching the focus on weight, Dr Himmelstein says. A lot of brainpower goes into monitoring kJs or carbs, she says - energy you'd be better off spending elsewhere. "Instead of trying to shrink your body, start to appreciate everything it does for you," Dr Hunger suggests. You'll be healthy and feel good no matter what your dress size.

Shedding kilos doesn't always lead to health gains

If low weight equalled good health, dropping kilos would automatically make people healthier – but that’s not what happens. Dr Hunger points to a meta-analysis that found that, even after dieters lost weight, their blood pressure, glucose and other blood markers weren’t significantly better when they were reevaluated two years later. Heavy people may make health gains when they’re put on a weight-reduction plan, but participants in many weight loss trials are urged to exercise – which other scientists suggest was more likely a health driver than the reduction of kilos.

Some healthcare providers can miss the mark completely

Most people with high body weight have a story about how their doctor judged or blamed them or didn’t listen, says Dr Himmelstein. It makes women avoid going to the GP because they don’t want to be fat-shamed, and then miss out on treatment or early detection. In other cases, health complaints that have nothing to do with weight are inaccurately blamed on a person’s size, so patients don’t get the right treatment. In this way, doctors’ bias can make people sicker – which might then add to the perception that all who are large-bodied are unhealthy. Problems, such as diabetes, cancer and autoimmune conditions, are especially important to identify early so they’re more easily treated, and health professionals’ emphasis on body weight may keep people from getting the best care.