Turning to butter and bacon to lose weight and boost health might not scream “winning plan” to everyone. But it makes perfect sense to those on the ketogenic diet (or “keto diet”), the latest “it” regimen that backs high-fat, moderate-protein, and low-carbohydrate eating. Of course, behind every popular keto diet, there’s controversy. Among the criticisms of the keto diet, skeptics say the plan is too restrictive, lacks nutritional balance, and hasn’t been studied for long-term effects (the keto diet ranked 39th out of 40 for Best Diets Overall 2017 by a U.S. News report). On the flip side, others—including some medical experts—believe a well-formulated keto diet is sustainable and meets essential nutrient needs; they also point to increasing research linking the keto diet to potential health benefits. Since then, there’s strong evidence that the keto diet helps with weight loss as well as type 2 diabetes, prediabetes, and metabolic syndrome, says Jeff Volek, Ph.D., RD, professor in the Department of Human Sciences at The Ohio State University in Columbus, Ohio and co-author of The Art and Science of Low Carbohydrate Living.
What Is a Ketogenic Diet?
On a ketogenic diet, you’re generally eating a keto diet that’s high in fat (roughly 70 percent of your total calories come from fat), moderate in protein (about 20 percent of your calories), and low in carbohydrate (about 5 percent of calories). By limiting carbohydrates (to usually less than 45 grams for the average person), your body lacks the glucose (from carbs) that it normally uses for energy, so it eventually switches over to burning fat as its primary fuel source instead; through a metabolic process called ketosis, the liver converts the fat into fragments of fatty acids called ketones, which power the brain and other organs and tissues. Everyone has to find their nutritional sweet spot for producing enough ketones and staying in ketosis, but “the core principle of the keto diet is to keep carbohydrate intake low enough, so your body continues producing ketones at elevated levels,” says Volek. “Your body adapts to this alternative fuel and becomes very efficient at breaking down and burning fat.”
Different Types of Ketogenic Diets
- Standard: This version—the type we’re discussing in this article—is consistently low-carb, moderate protein and high-fat, and the one that has been the most widely studied and shown to be beneficial for therapeutic uses, such as diabetes.
- Cyclical: Also referred to as “carb-cycling,” this keto diet involves injecting short periods of high-carb consumption (called “carb refeeds”) into a regular keto diet to replenish glycogen stores for muscle growth. This version isn’t well-studied and is aimed more at serious athletes and bodybuilders.
- Targeted: On a targeted keto diet, you consume carbohydrates around your workouts to improve athletic performance without knocking yourself out of ketosis for too long. This version is also geared toward hardcore exercisers.
Ketogenic Diet Benefits
Positive science on ketosis coupled with personal successes passed by word-of-mouth have driven more people to explore the ketogenic diet, says Volek. More recently, the keto diet hints at having a promising therapeutic role in cancer, Alzheimer’s, Parkinson’s and polycystic ovary syndrome (PCOS). Research is still early in many areas, but Volek suspects there will more definitive answers on the wider scope of the keto diet’s benefits within the next decade.
Benefit #1: Weight Loss
You may experience rapid weight loss in the first week due to fluid loss, but then after a few weeks, you’ll likely notice more pounds peeling away. Many reasons for this weight loss are being investigated, but the journal Obesity Reviews, reveals that ketosis suppresses your appetite, which squashes the desire to eat.
Benefit #2: Control Blood Sugar
Most carbs you consume are broken down into sugar that enters the bloodstream. When you rein in carbohydrates on the keto diet, you have lower levels of blood glucose (high blood glucose can lead to diabetes). A study in the journal Nutrition reveals that a keto diet improves blood glucose levels in type 2 diabetics more significantly than a low-calorie keto diet and can also decrease the dosage of your diabetes meds.
Benefit #3: Improve Cholesterol and Blood Pressure
A review of multiple studies in the journal Nutrients found that keto diets are connected to significant reductions in total cholesterol, increases in “good” HDL cholesterol levels, dips in triglycerides levels and decreases in “bad” LDL cholesterol; there are questions as to whether keto diet high in saturated fat negates these benefits. The same paper reports that a ketogenic may slightly reduce blood pressure, but science is still very scant on this point.
Benefit #4: Lower Inflammation
With inflammation driving most chronic diseases, the keto diet is anti-inflammatory and may help ease some inflammation-related pain conditions, according to researchers at Trinity College. One mechanism at play: The keto diet eliminates sugar and processed foods that can lead to oxidative stress in the body, a cause of chronic inflammation.
Benefit #5: Longer Life
This may be more of a maybe, but recent studies on mice fed a keto diet lived longer, according to Cell Metabolism. “Not only did these mice live longer, but they had also expanded health in terms of physical and cognitive functioning,” says Volek. “Meaning, they lived happy, healthy lives.” Obviously, human studies need to be performed.