What is a ketogenic diet?The ketogenic diet drastically lowers daily carb intake and replaces it with healthy fats. The standard keto dietary nutrient ratio is 75 percent fat, 20 percent protein, and 5 percent carbs. This is very different from the standard American diet:
|Standard American Diet||Ketogenic Diet|
|50 percent carbs||5 percent carbs|
|15 percent protein||20 percent protein|
|35 percent fat||75 percent fat|
Why keto worksThe body's primary fuel source is glucose, that is, sugar. When carbs are broken down, that's what's left in our systems. That's generally OK—but there's a point where it's too much. By eliminating most carbs from the diet, the keto diet brings sugar levels, and their dangerous spikes in blood sugar and insulin levels, way down. And what do our bodies do when starved of sugar? They burn the next most available fuel: the body's store of fat. And when the fat is depleted, our bodies are kept fueled up by compounds called ketones. Here's where we find ketones doing their healthy work:
- When your body uses ketones directly as its source of energy, you lose weight more readily because your body taps into your own fat stores for energy instead of the sugar you eat.
- Without surges of glucose, your body has improved energy levels because you can use your own body fat for energy—no sugar crashes or food comas. It takes only around half an hour for carbs to process into sugar—whereas protein is converted first into amino acids, and then, if not needed for muscle maintenance, glucose.
- Increased mental focus: Because fat is a more consistent source of energy than glucose, and is preferred by the brain, you don’t have ups and downs in mental energy and focus.
- Longevity and disease prevention: Ketosis has been shown to decrease inflammation, the source of nearly every kind of disease, and has been shown to reduce Alzheimer’s risk, and to benefit cancer patients and diabetics.
- Increased physical performance: Ketosis uses oxygen more efficiently and avoids physical crashes of low blood sugar.
- Reduced risk of heart disease, as natural fats and protein, instead of carbs, become the body's front line energy sources.
Starting upIt's different for everyone, of course. But many people starting off on the keto adventure have some less than pleasant moments. That should be no surprise. Kicking the habit. Let's not mince words—getting on the keto diet means getting off of a wickedly addictive substance called sugar. As with any addiction, the process can be challenging. Some people experience symptoms similar to a light flu. This is known as keto-flu. That means feeling tired, having dizzy spells, running a low fever, and having difficulty concentrating. You may crave sugar, feel slightly nauseous, have trouble sleeping, and become cranky or irritable. In most cases, this adjustment period only lasts about a week—but it's worth going through, not least because those withdrawal symptoms serve to underscore what a truly nasty habit sugar is. It makes you sick when you're on it, and makes it hard to get rid of. Muscle mass. As your sugar-hungry cells look for other sources of fuel, it's not just stored fat that it turns to. Muscle mass is another source, so some people may lose muscle. This is usually an effect of inadequate protein consumption, and can be fixed by ensuring adequate protein intake. Rash. It's rare, but some people find themselves developing a rash around the belly. This is called Prurigo Pigmentosa. It's not uncomfortable, and will go away if you up your carb intake temporarily. Of course you want to ensure that
Fat's chance to shineThough fat has come out from under its misguided reputation as the ultimate health threat, the keto diet's emphasis on plenty of fat still comes as a surprise to many people. A diet built on 75 percent fat—more than double the typical diet of 35 percent—seems counterintuitive. But now we know there's fat, and then there's fat. The keto diet's recommended fats are the kind called medium-chain triglycerides (MCTs). That's the fat found in coconut oil, avocados, butter, olive oil, lard, ghee, and essential fatty acids like omega-3. They earn keto's center stage because the body easily absorbs them, and sends them straight to the liver, where they're put to work right away to help deliver energy anywhere it's needed.
What's not on the keto menu?There's a lot that's to be avoided on a keto diet. Here's a partial list of carb-heavy grain no-nos:
- White Flour
- Most flours
- Wheat Flour
- Rice Flour
- Garlic Butter Brazilian Steak
- Low-Carb Salisbury Steak with Mushroom Gravy
- Zucchini “Pasta” with Chicken and Pistachios
- Creamy Tuscan Garlic Chicken
- 15-Minute Garlic Shrimp Zoodles
- Blackened Salmon with Avocado Salsa
- Asparagus, Lemon and Ricotta Stuffed Salmon Rolls
- Cashew Chicken
Pre-keto factorsBefore diving into a keto diet, you should get a good blood-screening test. This gives you and your doctor a chance to see what your levels of various nutrients and non-nutrients tell us—benchmarks you can refer back to in future screenings to see what's changed, or not. A standard hemoglobin A1C test is always a good place to start. It gives you a great long-term perspective on your body’s relationship with sugar…and how well it’s processing it. This also lets your doctor modify your keto diet. There can be, for example, a vegetarian version that replaces animal-derived fats with purely plant-based fats. For people in very good health, there's what's known as a "keto quickstart" diet, which reduces your time spent at the outset while your body adjusts to the keto regimen.
The ultimate fix—or fad?As I mentioned at the top, not everyone is on board the keto train. Critics contend the keto diet works only in the short term, and then only because much of the early weight loss is just the body shedding water, according to Lisa Cimperman, a clinical dietitian at Case Medical Center in Cleveland, and a spokesperson for the Academy of Nutrition and Dietetics. Cimperman says “Once your body enters ketosis, you also begin to lose muscle, become extremely fatigued, and eventually enter starvation mode. Then it actually becomes even harder to lose weight,” Another expert warns “Keto diets should only be used under clinical supervision and only for brief periods.” She allows that “They have worked successfully on some cancer patients in conjunction with chemotherapy to shrink tumors and to reduce seizures among people suffering from epilepsy.” But her bottom line is that a keto diet should only be considered in extreme cases. When widespread in the general population, she says, “It can do more harm than good. It can damage the heart, which is also a muscle,” and therefore exposed to the muscle mass loss mentioned. People with type 2 diabetes can benefit from weight loss and a reduced-carb diet because it will improve insulin sensitivity, Cimperman explained. "But there are many other ways to do it besides a fad diet that won’t keep weight off long-term,” she said. Ouch. A Harvard Health article argues that the diet is so restrictive that many people just can't stick with it for long. That's why there are so few long-term studies—not enough people last long enough to be considered "long-term." Others argue that the keto diet is dangerously deficient in fresh fruits and vegetables— a necessary rebalancer to counter the heavy load of fats and protein. To keto or not to keto is a matter that can be decided only in consultation with your doctor. If you have specific goals that you think keto can help you achieve, bring it up with your medical team at your next appointment. Take good care.
- Champion, "30 Ketogenic Dinners You Can Make in 30 Minutes or Less." Pure Wow. Published June 21, 2017. Last accessed June 29, 2018.
- "The Ultimate Guide to Ketosis" Perfect Keto. Published NA. Last accessed June 29, 2018.
- Goldstein, Valerie. "Can a Ketogenic Diet Help Prevent and Treat Heart Disease?" Keto Diet Blog. Published April 29, 2018. Last accessed June 29, 2018.
- Liberti, Maria V. and Locasale, Jason W. "The Warburg Effect: How Does it Benefit Cancer Cells?" Published January 5, 2016. Last accessed June 29, 2018.
- Isaacs, Tony "What Otto Warburg Actually Discovered About Cancer" The Truth About Cancer. Published NA. Last accessed June 29, 2018.
- "The Amazing Benefits Of A Ketogenic Diet" Health Scams Exposed. Published May 15, 2017. Last accessed June 29, 2018.
- Seegert, Liz "The Keto Diet Is Gaining Popularity, but Is It Safe?" Healthline. Published June 7, 2016. Last accessed June 29, 2018.
- Campos, Marcelo "Ketogenic diet: Is the ultimate low-carb diet good for you?" Harvard Health. Published July 27, 2017. Last accessed June 29, 2018.