Aseem Malhotra has been begging for his comeuppance ever since he started spouting his scientifically illiterate, factually inaccurate rubbish four years ago. He has suffered setbacks before but today he went too far, even for the 'public health' racket. Even his old buddies at Action on Sugar such as Simon Capewell and Jenny Rosborough have finally had enough. Public Health England, the Faculty for Public Health, the Royal Society for Public Health, the British Dietetic Association and more have all lined up to mock his latest headline-grabbing initiative.
I have written what I hope will be an obituary for his narcissistic, attention-seeking career as a TV doctor for the Spectator...
Do read the rest.
Within a year or two Malhotra will be earning his living selling diet books and delivering cherry-picked presentations to credulous low carb cultists on cruise ships. Mark my words.
I have written what I hope will be an obituary for his narcissistic, attention-seeking career as a TV doctor for the Spectator...
Action on Sugar, a small pressure group set up in 2013, have received a vast amount of media coverage by appealing to the public’s appetite for easy answers. Not only do they focus on a single nutrient, but they have a cartoon villain (‘Big Food’) and an easy answer that absolves consumers from having to take personal responsibility (food reformulation).
In their early days, their chief spokesman was Dr Aseem Malhotra, a Croydon-based cardiologist with a knack for sloganeering. To borrow a phrase from Peter Cook, Malhotra rose without trace. One minute he was writing factually inaccurate articles for the Observerabout ‘junk food’, the next minute he was describing himself as a ‘world leading expert in the prevention, diagnosis and treatment of heart disease’ who ‘reigns supreme in his fight to raise awareness about the health benefits of a sugar-free diet’.
Malhotra parted company with Action on Sugar some time ago, but he has remained a fixture on breakfast television ever since. Last year, he was in the news after making the extraordinary claim that there is no link between physical inactivity and obesity. Having fallen under the spell of Dr Robert Lustig, an American endocrinologist who blames obesity on high fructose corn syrup (a type of sugar that is barely consumed in the EU due to quotas), he drifted into the low-carb, high-fat (LCHF) movement via Gary Taubes and Nina Teicholz.
This is where this things start to get weird...
Do read the rest.
Within a year or two Malhotra will be earning his living selling diet books and delivering cherry-picked presentations to credulous low carb cultists on cruise ships. Mark my words.
TUESDAY, 10 MARCH 2015
Couch potatoes and hunter-gatherers
Further to Aseem Malhotra's absurd claims about obesity not being linked to physical activity, here he is at a recent conference last month making another of his frequent assertions—that there has been "little change in exercise levels in the past 30 years".
I want to focus on the second point on the slide.
Little change in exercise levels in the past 30 years whilst obesity has rocketed
Perhaps because this is a counter-intuitive claim in an era of office drones and couch potatoes, Malhotra goes to the trouble of providing a reference. It is a reference I have come across beforebecause Action on Sugar cited it in a briefing paper sent to politicians.
The title of the study - 'Hunter-gatherer energetics and human obesity' - provides a clue that it is not going to offer much evidence about changes in Western levels of physical obesity in the last thirty years. And it doesn't. It actually looks at a hunter-gatherer tribe in Tanzania, whose members apparently have similar levels of energy expenditure as that seen amongst a sample of Americans.
What is the relevance of this study? Presumably Malhotra's thinking goes like this.
1. The lifestyle of hunter-gatherers in Africa is similar to that of Westerners in days of yore.
2. Hunter-gatherers in Africa are no more physically active than Westerners today.
3. Levels of physical activity have not changed for thousands of years and therefore cannot have changed in the last few decades.
Hmm. This theory is problematic for a number of reasons. For a start, the study of Tanzanian bushmen actually did find higher levels of physical activity ("As expected, physical activity level, PAL, was greater among Hadza foragers than among Westerners.") It also found higher levels of physical activity amongst peasant farmers, in line with previous studies. It was only total energy expenditure after adjusting for height, weight etc. that was similar in both societies—a finding that appears to be due to physiological differences between the two groups.
(Incidentally, the authors note that "many hunter-gatherers seasonally consume a large portion of their daily calories as honey, which has high concentrations of glucose and fructose". This poses a bit of a problem for people like Malhotra who see fructose as the main cause of obesity and diabetes, both of which are vanishingly rare amongst tribesmen.)
But even if taken at face value, this is still only one study. If you look at the the evidence in the round, a rather different picture emerges...
Most analyses of hunter-gatherer diets assume caloric intakes of approximately 3000kcal day, a surprisingly large figure that exceeds typical contemporary intakes. The level of energy expenditure necessitated by pre-agricultural lifestyles, however, was much greater than that for average modern individuals. For instance, total energy expenditure in the !Kung and Ache peoples averaged 206kJ/kg/d, compared to roughly 134kJ/kg/d for contemporary humans.
Hunter-gatherers who consume 3000 calories a day rarely, if ever, become obese. Westerners who eat 3000 calories a day frequently become obese. The difference is that hunter-gatherers burn off all those calories whereas Westerners generally don't.
What does this tell us about physical activity levels over the last 30 years? Not very much, to be honest, but it is worth noting that in the mid-twentieth century the UK government recommended people eat 2,900 calories a day, based on good evidence showing that if people consumed less than that, they lost weight. Today, the government recommends people consume 2,250 calories a day (more for men, less for women). Why, if there has been no decline in energy expenditure, has the advice changed so much?
The fact is that the average Briton who consumed 2,700 calories in the 1940s would lose weight. Today, the average Briton who consumes 2,700 calories gains weight. Conversely, if the average Brit followed today's guidelines they would lose weight to a rapid and dangerous extent. The only rational explanation for this—supported by masses of empirical evidence—is that physical activity has declined over the years.
As I mentioned in a previous post, the decline in physical activity in the West is acknowledged by the World Health Organisation, Public Health England, the NHS, the Harvard School of Public Health and countless other organisations. If you want to challenge that view, you'd better have some pretty compelling evidence. Malhotra's killer piece of evidence—the one study that he repeatedly cites and puts up on slides at conferences—is not only of little relevance to the claim he is supposed to be debunking, but is an outlier even within its own narrow field.
All of which is a good indication that he hasn't got much evidence at all.
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