What is the Ketogenic Diet?
Bottom Line Up Front: A ketogenic diet is a low-carb, high-fat, moderate-protein diet used to lose weight.
As the name suggests, the ketogenic diet is a diet that GENerates KETones. Ketones are fatty-acid metabolites created by the liver as an alternative fuel source during periods of starvation or carbohydrate restriction.
Another name for the ketogenic diet is the keto diet, which can be further shortened to just keto.
The process of creating ketones in the liver is called ketogenesis.
The metabolic state of generating ketones is referred to as ketosis. If you’ve removed enough carbohydrates from your diet long enough, your liver will begin ketogenesis, start breaking down fatty acids to create ketones, and you will be “in” ketosis.
Why Do Keto?
There are a number of reasons to eat a ketogenic diet. Perhaps the most common medically accepted use of the ketogenic diet is as a therapy to treat epileptic seizures. It seems that ketones somehow downregulate excitatory neurotransmitters in the brain.
In other words, it’s “calming.”
Even if you don’t suffer from epilepsy, the same mechanism of the ketogenic diet that prevents seizures also seems to improve sleep quality—at least anecdotally.
There is also some evidence that ketogenic diets are useful in treating certain kinds of cancers.
But perhaps the most common reason that people “do keto,” however, is simple:
You’ve probably heard someone talk about “doing Atkins,” or “cutting carbs;” you’ve probably attempted a low-carb diet in the past. These types of diets are essentially popular variations of the ketogenic diet.
How To Do Keto?
In short order: eat a low carbohydrate, moderate protein, high fat diet
Low Carbohydrate: Eat no more than 40 grams of carbohydrates a day. No more than 20 grams a day is better. Zero carbohydrate consumption is perfectly OK as well.
These carbohydrate restrictions are an Absolute Requirement. While some individuals might get away with higher carbohydrate consumption, sticking to these numbers will ensure that you are in ketosis.
Moderate Protein: Eat the RDA minimum of .8 grams of protein per kilogram of bodyweight (.36 grams per pound of bodyweight). That’s 73 grams of protein for a 200 pound adult; more may or may not be better.
The protein recommendation is an Absolute Minimum. Odds are that if you’re eating keto you won’t have a problem getting enough protein. Whether you can eat too much protein, or if extremely high amounts of protein can “kick you out of ketosis,” is one of the more contentious debates in the keto community.
That said, there really isn’t any need for much more than 1 gram of protein per pound of bodyweight; and, technically speaking, protein can be converted into glucose which will lower ketone levels…
Suffice to say, don’t overthink it. But if you’re looking to maximize weight-loss or you’re really hung up on ketones levels, try to keep protein consumption closer to the minimum.
High Fat: The rest of your calories will come from fat.
The “high fat” fat recommendation is Relative.
Relative to even the “Standard American Diet” (SAD), the ketogenic diet is high in fat. However, there is no minimum fat requirement. There is also no maximum limit to how much fat you can eat, but please be reasonable.
Just because you can drown everything in butter, doesn’t mean you should.
At least not all the time.
Calories still count (kinda).
What About Alcohol?
At 8 calories per gram, alcohol is also a macronutrient; and, while it inhibits weight loss, is perfectly compatible with ketogenic diets provided that the beverage doesn’t contain too many carbohydrates.
Distilled liquors (gin, whiskey, vodka, etc.) contain zero carbohydrates.
Dry wines and champagne might have a couple grams of carbs per glass, if that.
Beers are generally best avoided– to the extent that they don’t take you over your daily carbohydrate limit of 20-40 grams per day. In other words, if you’ve only eaten 10 grams of carbs for the day then go ahead and enjoy the 10 grams of carbs in your beer.
***CAUTION*** Be extremely careful indulging in alcohol while eating a ketogenic diet. The internet is rife with anecdotes that suggest your ability to metabolize alcohol is greatly diminished while on keto and your tolerance greatly declines. You’ll get more intoxicated more quickly and hangovers are far more severe.
You’ve been warned.
What About Other Beverages (Coffee? Tea? Diet Soda?, etc.)
So long as your daily carbohydrate consumption doesn’t exceed your 20-40 grams per day limit, drink what you want.
Unsweetened coffee and tea are both zero carb.
Diet soda is zero carb; however, at least for some people, it might spike insulin and inhibit weight loss.
Personally, I only drink water and unsweetened coffee.
How Does Keto Work?
For someone following the USDA recommended dietary guidelines, that is to say eating carbohydrates and not in ketosis, their body runs entirely off of two fuel sources: fat (fatty acids) and carbohydrates (glucose). Fatty acids, however, are unable to cross the blood-brain barrier and fuel the brain. Hence, the brain is almost entirely reliant on glucose to meet its energy needs.
But what if you are following a ketogenic diet and are restricting carbohydrates? If fatty acids can’t cross the blood-brain barrier how can you meet your brain’s energy needs without carbohydrates?
Again, ketones are fatty-acid metabolites created by the liver as an alternative fuel source during periods of carbohydrate restriction.
Like glucose, ketones are able to cross the blood-brain barrier and supply your brain with the energy to replace those missing carbohydrates.
In short, your body creates ketones from fat to fuel the brain when you stop eating carbs.
No, How Does Keto Work to Help Me Lose Weight?
You gotta eat fat to burn fat.
Again, the average person gets their energy from two sources: fat and carbs. The body, however, has a preference for carbs.
That’s not to say that carbs are better than fat or that your body runs off carbs better than fat, what it means is that if it has access to both carbs and fat it prefers to burn carbs first.
Ask any diabetic: high blood sugar is toxic. So long as you’re eating carbohydrates your body will burn carbs before it burns fat to keep those levels in check.
And your body raises insulin levels to remove carbohydrates that aren’t burned off and store them in your fat cells.
Insulin is the primary hormone that regulates bodyweight and it’s particularly sensitive to carbohydrates.
It’s why diabetics who can’t produce enough insulin have high blood sugar levels.
It’s also why diabetics who don’t take insulin suffer from extreme weight-loss.
Don’t get me wrong, insulin is absolutely necessary for survival. Too much insulin, however, is unhealthy and leads to weight-gain.
Too much insulin is probably why you have such a hard time losing weight:
Excess Carbs > Excess Insulin > Excess Body Fat
But by eating a ketogenic diet and keeping carbohydrate consumption below 20-40 grams per day you will lower insulin.
Low insulin is what kick-starts ketosis. By removing carbohydrates and keeping insulin levels low, more fat is burned and converted into ketones.
So ketones by themselves don’t necessarily make you lose weight, they are a beneficial side effect of the lower insulin levels that are necessary to maximize fat loss.
I Thought I Just Had to Burn More Calories to Lose Weight?
How’s that been going for ya?
It’s true that burning more calories than you consume will result in weight loss.
However, such a simple-minded approach ignores the influence of hormones like insulin. Simply reducing the amount of calories you eat will also lower insulin levels. So what caused the weight loss? Was it the reduction in calories, or the simultaneous reduction in insulin that increased your body’s ability to burn stored bodyfat?
Think of it this way: If calories-in vs calories-out was the only thing that determined bodyweight, then 1,000 calories of soda would be no different than 1,000 calories of chicken breast, would be no different than 1,000 calories of spinach, would be no different than 1,000 calories of butter…
If you really believe that, then stop reading this and go back to simple calorie counting.
However, if you think there’s a chance that hormones might determine bodyweight, consider:
We know that insulin causes weight gain. It stands to reason that excess insulin causes excess weight gain, so keeping insulin levels low will keep bodyweight in check.
Insulin is sensitive to calories in general, but carbohydrates in particular.
Protein can also spike insulin levels, but not to the extent of carbohydrates.
Dietary fat has little impact on insulin levels.
So to minimize insulin and manage a healthy bodyweight, eat a diet that is:
Low Carbohydrate, Moderate Protein, High Fat
Sound like keto?
I Don’t Believe You, Keto is Just Calorie Restriction in Disguise!
That’s OK—embrace the gimmick!
A lot of people can’t get beyond calories-in vs calories-out; so, rather than try to convince them otherwise, it might be more helpful to highlight how the ketogenic diet makes calorie restriction easier.
The common argument is that removing a macronutrient (in this case carbohydrates) entirely from your diet is going to restrict calories by itself.
But if it really is a matter of calories-in vs calories-out, why have so many people had so much success with keto where calorie counting failed?
Keto kills your appetite.
If for no other reason, follow the ketogenic diet because it absolutely kills your appetite.
You’ll have to have some patience because it takes a while for your body to adapt, but after a month or so you will find yourself just naturally eating less—less food and less often.
There are a couple theories why:
Keto is Satiating: Meals that are higher in protein and fat make you feel fuller, faster.
Better Blood Sugar Control: We’re all familiar with the sugar crash from eating too many simple carbohydrates. After the initial spike in energy, your blood sugar crashes and you’re hungry again. Eating keto eliminates sugar from the diet which seems to result in more stable blood sugar levels.
Ketones: It’s suspected that ketones themselves are just naturally appetite suppressing.
So even if you believe that calorie restriction is the key to weight loss, don’t dismiss keto out of hand. It can be a useful tool for appetite control—provided you take the time to adapt.
The ketogenic diet is low carbohydrate, moderate protein, and high fat.
Many people have successfully lost weight on a ketogenic diet because it is uniquely suited for weight loss for two reasons:
1) Ketogenic diets maximize fat-burning by minimizing insulin
2) Ketogenic diets naturally restrict calories by suppressing appetite
If you’re interested in losing weight, I hope that you’ll give the ketogenic diet a try.
Even if you don’t buy the rationale behind the insulin hypothesis, I’m sure you’ll find success in your efforts to restrict calories with the appetite suppressing effects of the ketogenic diet.