Low-Fat or Low-Carb – Results Will Vary

It’s time to confess. We are tired of people – scientists, advocates, and health reporters alike – who claim they have the answer for weight loss. Or obesity. It’s just not true. For just about any option, the truth is that results will vary. Case in point: dietary strategies.

Right now, word of mouth and popular press suggest that low-carb diets are fantastically effective – especially ketogenic diets. Low-fat diets are passé.

But it’s all anecdotes. Look at the data and you’ll find that, on average, a low-carb dietary pattern works about as well as all the others. No better and no worse.

What Works for You?

If you want to understand this, take a look at the data on these two charts from the DIETFITS study. This was a large, randomized study to compare low-fat and low-carb dietary patterns. Overall, they found no difference in results between the two dietary patterns.

But the way individuals responded was tremendously variable. Some people actually gained weight on the diet. Most had lost about five kilos after 12 months. And then a few of them lost fantastic amounts of weight – up to 30 kilos.

Those folks are the exceptions. And they’re the ones whose testimonials you’ll read. Results not typical.

One Size Will Never Fit All

This leaves us fed up with evangelists for low-carb or keto diets. Their testimonials are inherently misleading. Different people respond differently to different options. The only thing that matters is what works for you. Figuring that out can be a matter of trial and error. A skilled dietitian can be a big help.

Likewise, scientists who espouse intermittent fasting, cutting refined carbs, or ketogenic diets as THE answer are barking up the wrong tree. Obesity has many causes. Many options can help in some people. Some diets help some people. Meds can help, too. Surgery can be especially helpful. But so far, we don’t have any easy answers that work for all.

Inflated Promises

Just as annoying, though somewhat different, are the inflated promises for various prevention and policy prescriptions. We are sick to death of hearing how well sugar taxes work. They may serve to rearrange patterns of food and beverage consumption. But we have zero evidence that they will have in impact on obesity. None.

Eat more fruits and veggies? Sure. Why not. Will promoting that reverse obesity trends? Maybe or maybe not.

What we need is less wishful pursuit of panaceas. Instead, we need a passion for objectivity. We need more curiosity about obesity itself, what causes it, what can reverse it, and what can actually prevent it. Results will vary and real solutions come in many incremental steps. But only if we look for them, rather than assuming we have them.

Click here for the DIETFITS study and here for further perspective on low-fat and low-carb diets. For more on the need for diverse approaches to obesity, click here and here.

Avocado on Board, photograph © Kjokkenutstyr.Net / flickr

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July 29, 2019