Are Low Carb Diets Like Atkins and the Ketogenic Diet Safe in the Long Term?

Listen to Dr. Neal address this topic on Episode 160 of the podcast Optimal Health Daily.

In a nutshell, lower-carbohydrate diets appear to be safe for most people in the long-term. And, if you’ve read or listened to me before, you know there’s a “but” in there somewhere… and you’d be right. Notice I said “lower” carbohydrate diets instead of “low-carbohydrate” diets. I have to mention something right off the bat: there are different definitions of what a “low-carbohydrate diet” really means.

If you follow the Atkins Diet for example, for the first 2 weeks you’re only eating about 20 grams of carbohydrate each day, mostly from vegetables. To put this in perspective, 1 slice of bread contains about 13 grams of carbohydrate, so you’d be pretty close to your max for the day right there.

The South Beach Diet recommends that folks consume no more than 120-140 grams of carbohydrate per day. Again for perspective, adults living in the U.S. and do not follow a low-carbohydrate diet, we consume on average about 350-400 grams of carbohydrate each day.

Then, there’s the Ketogenic diet which I have discussed before. Someone following the Ketogenic diet may only consume 50 grams of carbohydrate per day (or less).

Now it should be obvious that the definition of low-carb diets can vary greatly. When we look at the studies on low-carbohydrate dieting and their safety, it does seem to show that following a lower carbohydrate diet may be safe. Again, notice I said “lower” carbohydrate. Usually what we find is that researchers, depending on what they were trying to accomplish with their study, may put people on an Atkins-style diet or the South Beach diet or maybe a combination of the two. In fact, when I conducted research, I put people on a “modified” South Beach diet. What the heck does that even mean? Basically, we used the South Beach Diet as our guide, but we made some changes to it to make it easier for people to follow. Because researchers do this all the time, it’s hard to make true comparisons from one study to the next. Is the Atkins diet safest or South Beach? Or a modified version of the two? We don’t know because all of these are used in human studies.

And here’s the other problem. Most studies follow people on these diets for one year max. This means we don’t know what may happen if they were to continue following these diets for more than a year. Would we see their weight come back? Would their cholesterol levels suffer? At this time, we really don’t know. You may be wondering, “Well, why don’t we study people for longer… then, we’d have our answer!” Those types of long-term studies are very expensive. Also, it’s very difficult to get people to commit to a long-term diet study. Why? Because most folks can’t follow the prescribed diet for more than 6 months, let alone more than a year! In fact, when I conducted my research, we had a 50% dropout rate when that 1 year anniversary came around: we started with 180 people in our study and ended up with only 90 by the end. I mentioned this when I talked about the Ketogenic diet, too. We don’t know if it’s safe to follow in the long-term because most can’t stick to it for that long.

In my experience… I want to repeat that: in my experience (which means this not based on formal research), I have found the sweet spot for people, especially those that want to lose or maintain their weight is to consume about 50% of their calories from carbohydrate each day. That’s about 250 grams of carbohydrate per day. This means you could eat a cup of oatmeal in the morning, a sandwich with 2 slices of bread for lunch, and 1 cup of cooked pasta for dinner…throw in 2 servings of fruit and 5 servings of low-carbohydrate vegetables each day (like green
leafy veggies, tomatoes, broccoli, mushrooms, and so on) and you’d basically be at 250 grams of carbohydrate right there.

Sound reasonable? That’s because this is really about watching those carbohydrate portions to help yourself consume less as opposed to following a specific low-carbohydrate diet. And because this diet isn’t as extreme, it’s usually easier for people to follow as a long-term change.

For people with type 2 diabetes following a low-carbohydrate diet: this does happen, but usually it’s a lower carbohydrate diet as opposed to following Atkins, South Beach, or the Ketogenic diet. Those with type 2 diabetes may want to follow a lower carbohydrate diet because having diabetes prevents the body from being able to process carbohydrates properly. So by eating less carbs, the body is happy.

Are there any health risks associated with following a low-carbohydrate diet over the long-term? Again, we don’t know for sure, but a list of the typical side effects based on the research that has been conducted are:

  • fatigue
  • weakness
  • constipation
  • kidney stones and other kidney problems
  • bad breath

The bottom line is that for most folks, following a lower-carbohydrate diet is likely safe in the long-term but notice again, I said a “lower” carbohydrate diet. Going on a very low carbohydrate may be a different story.

Listen to Dr. Neal address this topic on Episode 160 of the podcast Optimal Health Daily.