What if I were to tell you that you’ve been lied to about carbs and fats for probably your entire life? Would you call me a liar? Would you say show me the data? Would I be a zealot of some form? Or would you be open to a paradigmatic shift in your thoughts about nutrition? There is a nutrition revolutionary storm a-brewin’ and it is high fat, very low carbohydrate, ketogenic dieting.
First, let’s address the immediate, visceral feelings you may be experiencing. “Won’t fat give me heart disease, diabetes, blahblah?” Yes. Of course it will… IF you eat fat AND carbs. “Well what if I eat carbs without fat?” It’s better than eating both, yes, but head-to-head, a ketogenic diet appears to be favorable for markers of metabolic syndrome and most preventable diseases. Carbohydrate inhibits fatty acid metabolism. When blood glucose and insulin are elevated, such as after carbohydrate ingestion, it is more difficult for our bodies to break down fats. Coupled with elevated insulin, this promotes fat storage, and in the absence of exercise, prolonged insulin elevation can lead to insulin resistance and diabetes. “Aren’t ketones bad for you?” Not necessarily, no. The level of ketone bodies induced by nutritional ketosis are much, much lower than with diabetic ketoacidosis, for example. Ketones are used as fuel, once the body adapts to using them in that manner.
“What exactly can you eat on a ketogenic diet?” Anything cut from an animal (yes bacon. yes 80/20 beef. yes chicken thighs. yes pork sausage. yes cow tongue… maybe not cow tongue), non-starchy vegetables (broccoli, kale, and others of the green variety), unsweetened yogurt, cheese, coconut products (especially coconut products) such as oil/butter/manna, nuts, avocado, seeds, full-fat salad dressings, butter, eggs, you can put cream in your coffee (REAL CREAM!), pork rinds, and mayonnaise. You can even work in chocolate and wine, ladies! I find one of the most fun things about keto is adapting your favorite recipes into a ketogenic version. Baked goods do not need to be ruled out, but you will most likely have to make them yourself with almond flour and artificial sweeteners. I find this to be highly advantageous over a high carb, low fat diet, since replacing carbohydrates in meals seems to be much easier than replacing fat. It’s also much easier to eat out, since most places cook their food in some form of fat. Just practice these words, “No bun, please.” Moreover, there are a ton of websites available that provide tasty “keto versions” of common recipes. Vegetables are also much more fun to eat when wrapped in bacon.
“What can you NOT eat?” Pretty much all fruit, desserts, breads, juice, beer (this one we can’t replace with fake hops, sorry Jimbo), grains of any variety (cereal, rice, quinoa, barley, wheat, etc.), starchy vegetables like potatoes, and pasta. “But I don’t think I can give up pizza.” Well you don’t have to, you just have to change it. Almond flour or cheese or meat (Meatza!) crust, low carb pizza sauce, cheese and meat/veggie toppings. Done (see the ruledme.com resource below). The best part is, if you really, just really can’t even, you can time carbohydrates near exercise without falling out of ketosis. In sedentary individuals, carbohydrates are typically capped at or before 50g per day or 5-10% of total calories while fat composes ~60-70% and protein the remainder. Athletes have a much higher carbohydrate tolerance already, and obviously, use more energy than some lump on a log. “Wellll how much can I have then?!”
It will vary based on activity level and other individual factors, so you need to determine it for yourself. You can do this via urinary ketone sticks (cheap option) or blood ketones (less cheap option, but better). First make sure you are in ketosis, then after you have your peri-workout carbs, test yourself again a few hours later. Though if you want the free option, I wouldn’t recommend trying to figure out how many carbs you can have, but you will feel generally lethargic while, and only while, adapting to the ketogenic diet. Athletes should be somewhere around 10-20% total calories from carbs, ~100g but I’ve seen some individuals between 150-200g and remain in ketosis, if carbs can be timed correctly and a high activity level is maintained. However, the idea of “maxing out” on how many carbs you can take in without losing nutritional ketosis is a bad one. Try to stay firmly in ketosis for the most benefit.
“So about that performance thing you mentioned…” Everything in this field of nutrition and athletics comes down to energy systems. The long duration system is the aerobic energy system, and it is a BEAST on the ketogenic diet. That is because the aerobic system can metabolize fats, and fats have the highest energy density. Marathoners and ultra-marathoners are already adopting the diet and setting records in the process because they are not running out of their preferred energy source of fats. But if you’re like me and don’t give a rats tail about running, cycling, or any other form of cardio, how can keto be beneficial?
The medium duration energy system is the anaerobic system. This energy system primarily uses carbohydrates. “Woah! Wait a minute. How do we fuel the anaerobic system if we’re not eating carbs?” Well the body makes carbs from fats and proteins. A person on a ketogenic diet won’t ever be devoid of glucose or glycogen. Muscle glycogen will be lower, but it will not be gone. Thus, anaerobic activity should not be grossly affected unless performed intermittently for a long time. So if you’re an athlete who does perform intermittent anaerobic activity for a long duration in a competitive setting, see two paragraphs ago and drink some carbs during your activity if you’re feeling weak or slow. The intermittent nature should allow for at least some carbohydrate replenishment through the body’s own process of gluconeogenesis, or formation of new glucose, but if you’re feeling as though some is needed, don’t deny it. Although, MCT’s are probably better (see coconut products).
In professional MMA fighters (intermittently anaerobic sport), they have reported equal or improved performance AND a cognitive benefit since they don’t experience hypoglycemia, they just use fats instead. No big deal to the keto-adapted body. However, so far, this has been anecdotal information (official investigation to be completed by the winter, hang tight!). “What about my gainz, bro?” In a resistance training clinical trial, the ketogenic diet actually INCREASED muscle gain MORE than high carb dieting, and AT THE SAME TIME reduced body fat. Strength was also unaffected compared to high carb. Too good to be true, right? Nope. It makes sense. The diet is known to be protein sparing and to have a beneficial effect on body fat from several other studies.
If you’re thinking of trying a keto diet, you must know three important things. First, do NOT be scared of eating foods that you previously believed to be “bad” like butter or bacon. Second, do not eat too much protein. Remember, the diet is fat based, do not be ket-bro-genic. Third, make sure you try the diet for at least 4 weeks before saying it is too hard or miserable or ineffective. It takes time to make the shift, but your body will thank you for it in the end. Finally, check out the sources below to gain some more information and for help on your journey.
ABOUT THE AUTHOR
Jordan Joy is currently a Research Coordinator at the MusclePharm Sports Science Institute. He is a CISSN certified sports nutritionist and CSCS certified strength coach. Jordan has his MS in Applied Nutrition with Northeastern University and is pursuing his PhD in Human Performance.