U.S. News & World Report recently published its 2020 best diet rankings. The ketogenic diet, you might have heard, did not fare so well[*]. It ranked second to last, placing 34th out of 35 diets.
The diet rankings were determined by a panel of “experts”—a handful of dieticians, professors, consultants, and writers with some sway in the field. They ranked keto for heart health, ease of use, weight loss, and several other categories. The categories were then amalgamated to calculate keto’s overall ranking, a miserable 2 stars out of 5.
If you’re on a keto diet (or considering one), this news may trouble you. Should you believe these experts or ignore them?
Neither. Don’t dismiss them, but don’t take their opinions as gospel. Examine the data for yourself.
After all, nutrition experts are notorious for being wrong. Take the food pyramid, for example. With bread on bottom and vegetables squirreled away on top, it was basically a template for metabolic syndrome.
Still, vestiges of the food pyramid remain. For instance, many authorities continue to recommend whole grains to treat type 2 diabetes. Nevermind that the latest science favors low-carb diets[*].
On that note, it’s time to review the specific categories for which keto was ranked. You’ll learn why the experts ranked keto so low, and whether or not their ranking aligns with the current science. Then you can decide for yourself if the ranking makes sense.
Sound good? Keep reading.
U.S. News Ranking: 2.8 stars out of 5
Their Opinion: The experts rated keto as “minimally effective” and “not safe” for preventing diabetes[*].
Worldwide, about 380 million people have type 2 diabetes — a condition marked by high insulin, high blood sugar, high blood pressure, and obesity[*].
Dietary management of type 2 diabetes is controversial. To start with, the standard recommendation involves significant amounts of carbohydrates. The American Diabetes Association, for instance, considers whole grains to be a “diabetes superfood”[*].
But since carbs raise blood sugar and insulin levels, they can exacerbate the metabolic issues at the heart of diabetes[*]. Rates of diabetes are spiraling upwards, so clearly, the whole grain strategy isn’t working. A new strategy is needed.
Enter the ketogenic diet. Consider the following evidence for keto treating and reversing diabetes:
- A 24-week randomized controlled trial on 84 diabetics found that a ketogenic diet was more effective than a low-glycemic diet (with whole grains) for lowering blood sugar, weaning off insulin, and promoting weight loss[*].
- In a recent controlled study, Virta Health put 218 type 2 diabetics on a ketogenic diet for a full year. The results? 60% reversed their diabetes, 94% reduced or eliminated insulin therapy, and the average weight loss was 30.4 pounds[*].
- According to a recent consensus report published in the journal Diabetes Care, low-carb diets have the “most evidence” (of any dietary intervention) for improving diabetic blood sugar levels[*].
These results show that, with proper supervision, keto is a safe and effective treatment for type 2 diabetes. Given this data, the U.S. News ranking is fairly baffling.
U.S. News Ranking: 1.4 stars out of 5
Their Opinion: Keto is “the hardest of the extremely hard!”, one expert is quoted as saying[*].
First of all, there’s truth here. Ruthlessly cutting carbs ain’t always easy.
Yes, keto takes good foods like potatoes, carrots, and many fruits off the table. Keto also eliminates many unhealthy foods like cake, cookies, chips, etc. But this isn’t such a bad thing if you happen to value your health.
Nevertheless, family gatherings, dates, and dinners can be a challenge on keto. Fortunately, many restaurants have keto-friendly options, and you’ll even find a dedicated keto menu here and there.
On the plus side, keto reduces your hunger hormone, ghrelin — so cravings shouldn’t be a huge problem[*]. Also, you don’t need to restrict calories on keto. (Calorie restriction virtually guarantees hunger pangs). Strangely enough, the calorie-restricting Biggest Loser Diet scored higher (2.3 stars) in this category.
Finally, keto needn’t be a permanent diet. You can go in and out. This is called keto cycling or carb cycling, and it works quite well for some folks.
U.S. News Ranking: 2 stars out of 5
Their Opinion: The U.S. News panel worries that eliminating whole grains and eating more saturated fat is bad for your heart.
Saturated fat is the bogeyman of heart disease. Widely feared, but not so dangerous.
In case you were wondering, the fear of saturated fat stems from bad science published in the 1950s[*]. More recent data, however, has set the record straight.
When you investigate how keto affects heart disease risk factors, you find controlled studies showing improvements in triglycerides, cholesterol, body weight, and blood pressure[*]. Things tend to move in the right direction, at least in obese populations.
Note, however, that a small subset of folks report elevations in LDL cholesterol (particularly LDL particle number) when following a keto diet. Make sure that you and your doctor are monitoring your bloodwork. If you see anything concerning, consider altering your diet.
U.S. News Ranking: 3.8 stars out of 5
Their Opinion: The experts rated keto highly in this category, tied for third overall.
There are a few reasons why. First, high-fat diets suppress hunger hormones like ghrelin and neuropeptide Y[*]. Less hunger, less overeating.
Second, unlike high-carb diets, a keto diet reduces insulin levels. Low insulin then signals the beta-oxidation of fatty acids in the liver[*]. Fat burning, in other words.
Finally, the keto diet eliminates sugar and processed foods — two main drivers of the obesity epidemic[*].
U.S. News Ranking: 2.2 stars out of 5
Their Opinion: Keto was dinged for having “insufficient evidence” for long-term weight loss.
Nutrition research is hard. Not only is it time-consuming, but it’s also expensive. And it’s tough to find funding for anything not resembling a blockbuster drug.
That’s why most controlled trials last weeks or months, not years. Sure, a two-year study with 300 participants comparing keto to five other diets would be awesome. But nobody is going to write that check.
That said, the ketogenic diet is probably the most studied weight loss diet on the planet. Some of these studies, like the ongoing research at Virta Health, extend out a full year with positive results[*].
On the other hand, the Biggest Loser diet (which oddly scored higher in this category) is a well-documented fail for long-term weight loss[*]. That’s because calorie restriction permanently reduces metabolic rate. When normal portions are resumed, the weight comes roaring back.
U.S. News Ranking: 1.4 stars out of 5
Their Opinion: The gripes against keto nutrition are driven by fears of micronutrient deficiencies and saturated fat.
It’s true: the keto dieter must be careful to avoid micronutrient deficiencies. That’s because keto removes many good sources of vitamins and minerals, like fruits and starchy vegetables.
The trick is to prioritize non-starchy veggies like spinach, kale, and broccoli. These plant foods are rich in magnesium, potassium, folate, and many other nutrients lacking in the modern diet.
What about saturated fat? Yes, that’s healthy too. Saturated fat:
- Is found in egg yolks, meat, fish, and butter — some of the most nutrient-dense foods on the planet
- Helps you absorb fat-soluble vitamins A, D, K, and E
- Is stable at high heat and safe for cooking[*]
- Has been shown to have zero link to heart disease[*][*]
The bottom line? Keto done right is compatible with proper nutrition.
U.S. News Ranking: 2 stars out of 5
Their Opinion: Again, the high-fat content of a keto diet was the major concern.
There isn’t much long-term data on the keto diet. Remember: It’s hard to do a 2-year controlled nutritional study.
Worth mentioning, however, are the Inuit — a culture who thrived for centuries on high-fat diets of seal and whale blubber. The Inuit hadn’t heard of the keto diet, but they were keto nonetheless.
“Such a diet would have led the populations to be in a permanent state of ketosis,” write the authors of a 2014 paper from the American Journal of Human Genetics[*].
But just because the Inuit did well on keto, it doesn’t mean you will. The clinical data suggests keto is safe and effective — short term — for a variety of applications (most notably weight loss), but this still leaves aside the individual component.
That’s why it’s crucial, on any diet, to monitor your energy levels, blood work, sleep, body weight, and any other metric that matters to you. If things are moving in the right direction, the diet is probably safe. If not, consider changing your approach.
Along with an understanding of the relevant science, this self-experimentation will serve you well. It will free you from the pull of splashy news stories, and allow you to make informed decisions about your health.