Are Keto Diets Healthy?
Keto diets are popping up in newsfeeds and headlines everywhere. Keto – or Ketogenic – refers to a restrictive diet that consists primarily of dietary fat, little protein, and nearly zero carbohydrates. The Keto diet was initially used as a method to treat the symptoms of epilepsy in the 1920s. You can read more on that here.
To determine whether the keto diet is “healthy” we need to define what we mean by “healthy.” For the sake of this discussion, let’s use body fat loss as our metric to define “healthy.” I’m not suggesting that losing body fat is the essence of health, but excess body fat remains to be the #1 risk factor for most lifestyle diseases.
How does one lose body fat?
Here we’ll make the distinction that most people can’t seem to grasp: weight loss is NOT fat loss. You may know this in the conscious part of your brain, but we’re always pulled back to the scale as our measuring tool. We love data and numbers so the scale becomes the least expensive and readily available measuring stick for progress. But it doesn’t tell the whole story.
What did life look like before a keto diet?
This is the first question I ask of anyone who has seen rapid weight loss on a keto diet. More often than not, the answer involves junk food, a ton of sugar, minimal protein, and zero plants. These foods have an inflammatory response (bloating). They’re also typically very high in sodium (water weight) and contain little to no fiber.
A keto diet — by nature — limits inflammatory foods, “empty” calories, and encourages you to eat vegetables. So right off the bat, you don’t feel bloated, you’re losing water weight, and you’re consuming WAY more fiber and micro-nutrients than before. Combine that with nearly zero carbohydrates (carbs transport water to your cells), and you have the perfect recipe for rapid weight loss. But is that weight fat? Probably not.
Is “fat burning” mode a real thing?
The keto diet reports that your body enters a state of using fat as fuel through your body’s production of ketones. This can be difficult to measure without some pretty sophisticated and very expensive equipment. So we resort to the scale as our measuring stick. But, we’re still humans on earth and bound by the pesky laws of physics. Therefore, fat can only be lost at a rate of 1-2 pounds per week. Regardless of the diet you choose, if you’re losing more than 1-2 pounds per week you’re losing some combination of water and muscle.
The carbohydrate debate – what does real science say?
Carbs are the most hotly-debated macronutrient in all of nutrition. But what does science say about carbohydrates? Not theoretical science but actual peer-reviewed, repeatable, controlled-study science. Wait for it… CARBS DON’T MATTER.
That’s right. And it should be expected if you really understand how hard science works. Hard science moves at a glacier’s pace. It’s slow, incremental, and builds upon itself. There have been no scientific “discoveries” as ground-breaking and game-changing as your Instagram newsfeed reports.
You can check out this meta-analysis of all the high/low carb studies. Here’s another study that shows that calories, not carbs are the #1 factor in weight loss.
Keto diets aren’t inherently healthy or unhealthy. The fat loss benefits of keto can be achieved with other methods. But, some people like the “rules” associated with keto. And that’s fine if it’s sustainable for you. I hope your takeaway is that there is no magic bullet for fat loss. There’s no secret diet that you’ve yet to discover. Sustainability is the key to any diet you choose – keto or otherwise.
Here’s a challenge: If you’re considering a change to keto run a little self-experiment. Instead of going from junk food to keto go to a diet rich in plants, varied carbohydrates, healthy fat, and adequate protein. Science shows that you’ll see the same fat loss results as a low-carb, high-fat diet and chances are it’s a lot more sustainable.
What are your thoughts? Have you tried keto?
For more info and tips, watch this video with Sabrena Jo – Chief Science Officer for the American Council on Exercise: