Even just a few years ago, a diet comprised primarily of high-fat foods such as butter, cream and bacon would have seemed a recipe for health disaster. But fat, it seems, is no longer public enemy No. 1. The very-low-carbohydrate, high-fat ketogenic diet (“keto” for short) is making waves as the latest celebrity weight loss craze. But does it work? Is it safe? Are there additional benefits to going keto for those who are also eating gluten free?
The genesis of ketogenic
Despite its recent popularity, the ketogenic diet isn’t new. Nearly a hundred years ago, it became a popular treatment for children with epilepsy, a seizure disorder. Before the 1920s, medications for epilepsy were limited and not always effective. Researchers noted that after two to three days of fasting, however, seizure activity decreased. This was thought to be a result of a metabolic change in the brain, from burning carbohydrates to utilizing ketone bodies from fat as the primary fuel.
Because long-term fasting isn’t an option, researchers discovered that depriving the brain of carbohydrates produced many of the same beneficial effects. The first documented ketogenic diet plans were similar to what is used today for seizure control, with as many as 90 percent of calories in the diet coming from fat. The diet fell out of fashion in the late 1930s as a result of the discovery of more effective seizure-control medications, although it has enjoyed a resurgence in recent years for children with epilepsy that doesn’t respond well to medications.
Ketosis is a normal body process that occurs when the body runs out of glucose for energy and switches to burning fat. This process produces ketones. It can occur as a byproduct of starvation, and it can also occur in those with poorly controlled type 1 diabetes. Ketosis can also result from severely limiting carbohydrates (typically less than 30 to 50 grams per day).
As the body transitions into ketosis, a person may experience some side effects. The first, known as the “keto flu,” entails a few days of nausea, fatigue, brain fog, decreased ability to exercise and increased hunger. Fortunately, these symptoms are temporary as the body transitions from burning carbohydrates to burning fat. Bad breath may also occur as blood acetone levels rise, but this usually goes away within a few weeks. People in ketosis may also experience leg cramps, constipation and elevated heart rate.
Weight, cholesterol and blood sugar benefits
Low-carb dieting is not new, with studies demonstrating that it works—at least in the short term—and is generally safe. The ketogenic diet is just the latest version to garner headlines. While studies do show that cutting carbohydrates results in weight loss, the mechanism of action remains controversial. One theory is that the higher protein content of the diet results in feeling more satisfied and therefore less hungry. This leads to taking in fewer calories overall, which leads to weight loss. Other research shows that ketosis produces beneficial effects on the hormones that trigger hunger and being in ketosis may decrease appetite.
Some dietitians even utilize it in their personal and professional practice. Franziska Spritzler, RD, CDE, author of the blog Low Carb Dietitian (lowcarbdietitian.com), began the keto diet a few years ago when her blood sugar began rising after meals. “I was thin and didn’t have any signs of insulin resistance, but my post-meal blood sugars were much higher than they should have been, even though I was eating plenty of fiber,” she says. Spritzler began to wonder if this way of eating would benefit others who struggled with blood sugar levels. “I began research on carb restriction for diabetes, and I was amazed to find many studies that supported this way of eating for blood sugar and weight control,” she says.
Spritzler sees many benefits for her patients. “Appetite is suppressed, and there is the ability to go several hours without eating. This is obviously a major benefit for those who struggle with their weight and are always hungry,” she notes. “It’s also great for busy people who don’t have time to snack and may need to delay or skip meals.”
For those with diabetes, research shows that banishing carbohydrates leads to weight loss and decreased need for diabetes medications. “For people with prediabetes, metabolic syndrome and polycystic ovarian syndrome [PCOS], eating a ketogenic diet can help keep their insulin levels under control,” Spritzler advises. “Plus, I notice that there is increased energy when eating low carb—a benefit for everyone!”
A high-fat diet may bring to mind heart disease, but the research on low-carb diets and cholesterol levels are, for the most part, favorable. Some studies on children who follow the ketogenic diet for epilepsy do show increased levels of bad cholesterol (LDL) and triglycerides, at least for the first few months after starting the plan. However, research in adults has shown that “good” cholesterol levels (HDL) rise and triglycerides decrease when cutting carbohydrates. It is important to note that the majority of studies involving the ketogenic diet are of short duration, so long-term effects are not necessarily known.
In addition to diabetes and weight control, new research may point to a role for the ketogenic diet in the treatment of certain cancers and neurological disorders such as Alzheimer’s disease and Parkinson’s disease.
Spritzler does note that some people should not attempt a ketogenic diet. “There are certain conditions in which the ketogenic diet is contraindicated,” she advises. “Most of them are genetic abnormalities involving an enzyme deficiency that would have been identified early in life [see sidebar, below].” Spritzler advises those with an existing disease or condition to discuss a ketogenic diet with their doctor before starting one: “Especially patients who have a history of pancreatitis, kidney failure, active gallbladder disease, impaired liver function, impaired fat digestion, gastric bypass surgery or someone who is pregnant or breastfeeding.”
Eating gluten free and keto
The ketogenic diet restricts all grains, so it may be a natural transition for someone who is eating gluten free. Spritzler sees only benefits. “I think it’s an ideal way of eating for those with celiac disease and gluten intolerance because a strict low-carb/high-fat or keto diet doesn’t allow bread, grains or grain-based additives.”
Elana Amsterdam, New York Times-bestselling author and founder of Elana’s Pantry, a website devoted to gluten-free and grain-free recipes, also sees the connection. “If you’re already eating a healthy gluten-free diet that is free of processed foods, the next step would be eliminating grains, plus corn and potatoes, as well as fruit.” Amsterdam has found personal benefits in following the ketogenic diet. “It has helped both my gut and brain function better.”
Amsterdam recommends almond flour for those who are gluten free and eating ketogenic. “It’s a standalone flour that does not require a combination of other flours to ‘enhance’ it. It tastes incredible in baked goods and is high-fat and low-carb, making it the optimal flour for those following a keto diet.”
Giving up all grains and fruit can lead to other issues—in particular, constipation, which is already an issue for so many who need to eat gluten free. Spritzler recommends lower-carb fruits like blackberries and raspberries, as well as avocado, flax and chia seeds, cruciferous vegetables such as broccoli and cauliflower, and almonds. “To avoid constipation, I recommend getting a serving of one of these higher-fiber foods at each meal,” she advises.
Restaurants, already a challenge for those who are gluten free, may require some additional planning to remain on the keto diet. “You have to plan ahead for trips, dining out and celebrations,” says Spritzler. “Always have low-carb foods on hand in case you find yourself surrounded by high-carb foods. For example, low-carb side dishes you can try include cauliflower rice or cauliflower mash.”
Sticking to the plan
Research shows that while many people lose weight when attempting a diet, very few can keep it off. The keto diet is no different in this regard, and straying from the very strict regimen typically means regaining lost pounds. While research supports low-carb dieting in the short term, most studies in children and adults show that long-term adherence is lacking. Spritzler admits she’s seen mixed results with her clients. “Some people do very well [on the ketogenic diet] and never go back to former comfort foods, especially after they’ve experienced its many positive effects on health,” she says. “But some can’t resist temptation, especially when they live with family members who don’t follow the diet. Others get bored with low-carb options, or they hit a weight-loss plateau that occurs with all diets.”
Spritzler urges her patients to stay positive, focusing on what they can have instead of what they can’t. “I encourage my patients to make a list of the reasons that are important to them to stay keto, and review it frequently.” Amsterdam agrees: “If you try it for a month and see that you feel better, then staying on the diet isn’t as challenging because the gains are so high. Everything in life is a trade-off.”
Genetic conditions where the ketogenic diet would be contraindicated
- Carnitine deficiency (primary)
- Carnitine palmitoyltransferase (CPT) I or II deficiency
- Carnitine translocase deficiency
- Beta-oxidation defects
- Mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (mHMGS) deficiency
- Medium-chain acyl-CoA dehydrogenase deficiency (MCAD)
- Long-chain acyl dehydrogenase deficiency (LCAD)
- Short-chain acyl-CoA dehydrogenase deficiency (SCAD)
- Long-chain 3-hydroxyacyl-CoA deficiency
- Medium-chain 3-hydroxyacyl-CoA deficiency
- Pyruvate carboxylase deficiency
Source: Franziska Sprtizler, RD, CDE