Yes, Calories Still Count When It Comes to Weight Loss

Yoni Freedhoff, MD


September 23, 2021

The past 10 days have seen a flurry of press releases, news articles, and breathless social media coverage of a perspective claiming that there's a new paradigm and diet to explain away obesity and that calories don't count.

The paradigm? Well, it's been around for some time now and it's known as the carbohydrate-insulin model. In the simplest of terms, this posits that overeating itself doesn't cause obesity but rather it's what you eat, and more specifically, the carbs.

Huzzah! No doubt obesity will soon be a thing of the calorie-confused past.

But wait — we've been here before, because this is the same low-carb approach that virtually all dieters have tried at some point in their lives, first lauded publicly by William Banting in 1863 and then catapulted to all dieters by Dr Atkins as the "high-calorie way to slim together" in his 1972 book, Diet Revolution, which has since sold over 15 million copies.

Having worked with thousands upon thousands of patients in my obesity medicine practice over the course of the past 18 years, I can tell you that virtually all of them have tried low-carb diets, most more than once. It seems to me that if low-carb truly was a miraculous paradigm, I wouldn't be meeting them.

Now, don't get me wrong — I'm all for low-carb diets. In fact, in both our office and our online programs we routinely prescribe them to interested patients. That said, we'll prescribe any diet that a patient thinks they might be able to enjoyably sustain, because when it comes to long-term success, adherence is king.

Let's put aside the fact that long-term trials of low-carb diets show that they don't work markedly better or worse than low-fat diets, and examine this underlying "calories don't count; there's a new paradigm to consider" business.

The latter concept is just bizarre, given that in the past few years we've seen the publication of multiple studies evaluating new weight loss medications which work via simple caloric reductions and in which the outcomes are dramatically better than those seen with low-carb dieting.

It's also bizarre given that there isn't even a robust mouse model where obesity increases with the isocaloric intake of carbs vs fat — and there's a mouse model for pretty much everything.

While it's easy to understand why people whose entire research careers are devoted to low-carb diets want to frame this new paper as novel and earth-shattering, and why clinicians who run exclusively low-carb diet clinics are thumping their chests, it's far more difficult to explain the excitement and framing from credible media, unless of course it's simply for clicks.

After all, who doesn't want to read about the new miracle diet even if it's anything but new?

And really, nowadays it seems to be almost entirely the low-carb camp putting forward the false dichotomy that when it comes to weight and/or health, it's either about the quantity or about the quality of calories, but not both.

But of course, it is about both, which is what every nonzealous clinician and researcher out there has been saying for decades.

Depressingly, this exhausted and manufactured public debate isn't likely to meaningfully matter to people with obesity, for whom the medical benefits and risk reductions of weight loss are highly significant.

Worse is the notion that there's one best or right diet, and prescribing or promoting only that one may hinder treatment, if believed.

Just as there aren't cardiologists who exclusively prescribe ACE inhibitors over all other antihypertensives, there shouldn't be clinicians comfortable with prescribing just low-carb diets over all others.

I think it's also important in any article discussing dieting for weight management to note that there are thousands of genes and dozens of hormones involved in our eating behaviors and, consequently, our weights. From metabolism to hunger to cravings to satiety to the impact that food has on our emotions — and more — these genes and hormones aren't yet routinely testable, let alone changeable.

It's also important to note that there is tremendous privilege involved in mustering the time, energy, and attention to focus on lifestyle changes that, by definition, need to be sustained to have a long-term impact.

The notion that obesity "is a choice" and that if a person just wants it badly enough, tries hard enough, and here perhaps, eats few enough carbs, they will of course succeed, just fuels weight bias, both in society and among the medical community. Moreover, the notion that there are magic diets is the lifeblood of predators and quacks.

If weight loss were as simple as eating fewer carbs, you might think that the two thirds of Americans who diet every year would have found some success by now. You might also think that the chest-thumping low-carb researchers and clinicians would have found success too in the form of reproducible clinical trials that demonstrate low-carb diets to be broadly and highly effective and sustainable for everyone rather than, as with all diets, just the select few who happen to enjoy them.

As I co-wrote in The Lancet a number of years ago, when it comes to weight loss, we need help, not hype. This? This was hype.

Yoni Freedhoff, MD, is an associate professor of family medicine at the University of Ottawa and medical director of the Bariatric Medical Institute, a nonsurgical weight management center. He is one of Canada's most outspoken obesity experts and the author of The Diet Fix: Why Diets Fail and How to Make Yours Work.

Follow Yoni Freedhoff on Twitter: @YoniFreedhoff

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