Although many hypotheses have been put forward to explain how the ketogenic diet works, it remains a mystery. Disproven hypotheses include systemic acidosis (high levels of acid in the blood), electrolyte changes and hypoglycaemia (low blood glucose). Although many biochemical changes are known to occur in the brain of a patient on the ketogenic diet, it is not known which of these has an anticonvulsant effect. The lack of understanding in this area is similar to the situation with many anticonvulsant drugs.
Wondering what fits into a keto diet — and what doesn’t? “It’s so important to know what foods you’ll be eating before you start, and how to incorporate more fats into your diet,” says Kristen Mancinelli, RD, author of The Ketogenic Diet: A Scientifically Proven Approach to Fast, Healthy Weight Loss, who is based in New York City. We asked her for some guidelines.
The keto diet changes the way your body converts food into energy. Eating a lot of fat and very few carbs puts you in ketosis, a metabolic state where your body burns fat instead of carbs for fuel. When your body is unable to get glucose from carbs, your liver converts fatty acids from your diet into ketones, an alternative source of energy. Burning ketones in place of glucose reduces inflammation and spurs weight loss.
A ketogenic diet is comprised of approximately 10% of daily calories coming from healthy carbohydrates such as leafy greens, nonstarchy vegetables, and limited amounts of legumes and berries; 20% of daily calories coming from proteins such as omega-3-rich fish and grass-fed animal protein; and ~70% of daily calories coming from high-quality fats such as avocado, unsaturated and medium-chain triglyceride oils, nuts and seeds, and coconut.
The keto diet is one of the most effective that I’ve come across and one of the more straightforward (as opposed to easy!) to follow. In a nutshell, when you’re on a keto diet, you eat a very low-carb, high-fat diet. That means goodbye pasta and bread, hello cheese and oils. It’s pretty much the opposite of what we’ve been taught our entire lives. But it works if you follow the keto diet food list. Plus, you can make many favorite recipes keto-friendly.
As I wrote in op-eds for the Wall Street Journal61 and Medscape,62 the Lancet Public Health study is based on very thin data. The questionnaire underlying the report left out questions regarding popular foods, such as pizza and energy bars, and did not consider alcohol consumption. Moreover, the “low-carb” diet group in this study included people eating up to 37% of calories as carbohydrates—not low-carb according to the latest science. Ultimately, this is the kind of data that can show association but not establish causation, which means it is the kind of data one can use to generate hypotheses but not prove them. This kind of data would never be considered sufficient to approve a drug, for instance. The same standards should be applied to diet. Quite a few researchers, including myself, had our critiques published in Lancet Public Health.63 The authors replied but did not respond to most of the criticisms.
A ketogenic diet could be an interesting alternative to treat certain conditions, and may accelerate weight loss. But it is hard to follow and it can be heavy on red meat and other fatty, processed, and salty foods that are notoriously unhealthy. We also do not know much about its long-term effects, probably because it’s so hard to stick with that people can’t eat this way for a long time. It is also important to remember that “yo-yo diets” that lead to rapid weight loss fluctuation are associated with increased mortality. Instead of engaging in the next popular diet that would last only a few weeks to months (for most people that includes a ketogenic diet), try to embrace change that is sustainable over the long term. A balanced, unprocessed diet, rich in very colorful fruits and vegetables, lean meats, fish, whole grains, nuts, seeds, olive oil, and lots of water seems to have the best evidence for a long, healthier, vibrant life.
From the founding of the United States to about the 1940’s, obesity wasn’t a problem for the average American. There just wasn’t that many pastries, desserts and junk foods around. Only the rich could afford to be fat. The rest of the folks ate meats, vegetables, fats and had very little sugars. Mom cooked everything with bacon fat. That’s a rationale Keto diet. Poor folks were always slim in those days. Now, with the proliferation of CHEAP junk food, everyone is fat.
These chewy cookies take the same amount of prep and ingredients compared to dirty keto cookies — and the results are packed with nutrients and rich flavor. With a dough made out of almond meal, gut-loving collagen protein, cocoa powder, and melty chunks of dark chocolate, this recipe bakes up into a sinful-tasting dessert with benefits. Just 2.5 net carbs per cookie.
Dr. Campos, it is so discouraging to see that you disparage the ketogenic diet based on your assumption that it is very heavy in poor quality processed meats. No diet that relies on processed foods can be viewed as “healthy”. Become better informed by getting up to speed with what Jeff Volek, RD, PhD, calls a “well-formulated ketogenic diet.” Also, learn more about the potential of the diet to slow cancer progression (my specialty). You owe it to your patients who are depending on you for advice. Present them with facts, not opinions.
In fact, patients with gastroesophageal reflux disease (GERD) have been shown to improve after eating very low carbohydrate diets.31, 32 Another study found increased carb-intake worsened GERD, while a high-fat, low-carbohydrate diet reduced symptoms.33 And two studies have linked esophageal diseases, including Barrett’s esophagus (BE)34 and GERD,35 to sugar and carbohydrate intake.
My principal hope in this article is to provide journalists with a resource to do what basic journalism demands, namely to ensure that stories are scientifically balanced and accurate. At the end of this post I provide contacts for some of the credentialed experts who helped me compile this research. Reporters, please seek out these or other low-carb diet experts so you can provide accurate, up-to-date information for your readers.
Con: Results can vary depending on how much fluid you drink. By drinking more water, you dilute the concentration of ketones in the urine and thus a lower level of ketones will be detected on the strips. The strips don’t show a precise ketone level. Finally, and most importantly, as you become increasingly keto-adapted and your body reabsorbs ketones from the urine, urine strips may become unreliable, even if you’re in ketosis.