Greater satiety.
Reduced hunger.
Increased fat burning.
Rapid weight loss.
These are but a few of the claims mentioned when discussing the ketogenic diet.
Few diets over the years have experienced the sustained popularity that the keto diet has enjoyed, and if you’re interested in losing weight, you’ve probably wondered if you should follow a ketogenic diet as well as is it necessary to follow one in order to lose weight.
In this article, we’ll help you answer both of those questions, but first, let’s do a brief review of what is a keto diet?
What is Keto?
Keto is short for ketogenic and it describes a diet that is very high in dietary fat, moderate in protein, and ultra-low in carbohydrates.
It was originally developed in a clinical setting to treat epileptic seizures in children.
For centuries, fasting has been used as a remedy for many common illnesses. The one issue with fasting is that you’re depriving the body of calories, and the body can only sustain itself for so long before it needs food or else it will cease to survive (i.e. die).
Doctors realized that when they fed the children a diet that contained little to no carbohydrates and a lot of dietary fat it mimicked the effects of fasting, yet supplied patients with enough calories to sustain life.
Typically, ketogenic diets have an individual consume 70-75% of their daily calories from fat, 20-25% from protein and ~5% from carbohydrates.
To put this in perspective, the average person can only consume ~50 grams of net carbohydrates per day and still remain in a state of ketosis.
What is Ketosis?
Under normal everyday circumstances, our bodies primarily run on glucose. And, glucose and glycogen (the storage form of glucose in skeletal muscles) serves as the main fuel that powers muscle contractions during high-intensity exercises, such as weightlifting, sprinting, and jumping.
We obtain this glucose from the digestion of carbohydrate-containing foods like fruits, vegetables, and whole grains.
However, when the body is deprived of glucose for prolonged periods of time (such as when you’re fasting or following a very low-carb diet), it runs on a “backup” fuel system called ketone bodies, or simply ketones.
Ketones are byproducts resulting from the breakdown of fatty acids in the liver.
While you’re in this ketogenic state, you’ll often hear keto proponents say that you’re “burning fat for fuel.”
And this is certainly true when deprived of glucose, the body does burn fat for energy.
However, just because you are burning fat for fuel does not actually mean that you are losing body fat, which brings us to our next point...
Do I Have to Go Keto to Burn Fat and Lose Weight?
In a word, no.
You do not have to adopt a ketogenic diet in order to lose body fat.
Remember, in order to lose weight, you must be in a negative energy balance. This means that you must burn more calories than you consume in a given day.
As such, you can follow any number of diets (Mediterranean, IIFYM, Paleo, etc.) and still lose weight.
Just because you are “burning more fat for fuel” doesn’t inherently mean that you’re actually losing weight.
For example, let’s say that your maintenance calories (the number of calories you need to eat to maintain your body weight) is 2000.
If you consume 2000 calories of food while following a ketogenic diet, you will certainly be burning fat for fuel, but you will not lose weight for the simple fact that you are not in a calorie deficit.
As another example, let’s say that you are following a more balanced diet containing 1700 calories per day, and this diet has you consuming 40% of your calories from carbohydrates and 30% each of protein and fat.
Following this diet, you will lose weight (due to the calorie deficit), yet you will not be in ketosis.
And the reason for this is simple -- to lose weight you have to be in an energy deficit.
This is why a number of studies have shown that the ketogenic diet is no more effective than lower-fat, higher carbohydrate diets of similar energy and protein content.[1,2,3]
Furthermore, a 2014 meta-analysis concluded:
“Trials show weight loss in the short-term irrespective of whether the diet is low CHO or balanced. There is probably little or no difference in weight loss and changes in cardiovascular risk factors up to two years of follow-up when overweight and obese adults, with or without type 2 diabetes, are randomized to low CHO diets and isoenergetic balanced weight-loss diets.”[4]
You see, when you consume fewer calories than your body requires consistently, the body is forced to turn to its energy reserves (body fat) to get the energy it needs to carry out the multitude of functions it does on a daily basis, regardless if you’re on a high carb, low-carb, or zero carb diet.
This brings us to the final point...
The Biggest Factor to Consider When Dieting for Fat Loss
Low-fat, high-fat, high-carb, no carb -- they can all work for losing weight.
But, losing weight isn’t the greatest challenge for the average dieter. The greatest challenge lies in keeping the weight off.
And, in order for you to maintain your body transformation, your diet has to be sustainable, meaning that you can adhere (stick) to it.
This is why the adherence trumps all when it comes to dieting for fat loss.
What that means is that a diet is only as effective as your ability to follow it day in, day out.
And, here lies the great downfall of keto for the average diet -- it is incredibly restrictive and it’s not the easiest diet to follow...not by a long shot.
Not only do you have to severely restrict (avoid) carbohydrates, you also have to be fairly meticulous about your protein intake, as consuming too much protein at one time can result in gluconeogenesis -- the production of glucose from noncarbohydrate sources -- which kicks you out of ketosis.
It’s also important to consider your own dieting history.
If you’re someone who has struggled to follow any sort of healthy eating plan for any prolonged period of time, what makes you think you’ll be able to adhere to an extreme elimination diet like keto for any considerable length of time?
Sure, you might be able to follow it for a week or two, but living a healthy lifestyle is finding a diet and training program that you can stick to day in and day out for weeks, months, and years.
For the average person, keto is simple too tedious.
To top it off, keto diets typically also can lead to decreased performance in high-intensity forms of exercise -- field sports, sprinting, weight lifting, basketball, etc.[5,6,7]
The reason for this is that high-intensity training relies mostly on glycogen (glucose), which is virtually nonexistent when following a keto diet.
Lastly, very low-carb or ketogenic diets can also make it harder to maintain sufficient levels of intensity during training, which is essential to retaining muscle mass while losing fat.
Takeaway
The ketogenic diet is a high-fat, very low-carb diet that is immensely popular right now. It can help people lose weight, but it is absolutely not necessary to follow in order to burn body fat and lose weight.
To shed unwanted body fat, all you need to do is adhere to a consistent calorie deficit and consume enough dietary protein (to protect lean muscle mass from breakdown).
Losing weight and keeping it off all comes back to your ability to stick to a given diet for the long term. If higher fat, lower carb diets keep you feeling satisfied and less hungry, then go for it. But by no means are they a “must” in order to lose weight.
References
- Phillips SA, Jurva JW, Syed AQ, et al. Benefit of low-fat over low-carbohydrate diet on endothelial health in obesity. Hypertension. 2008;51(2):376–382. doi:10.1161/HYPERTENSIONAHA.107.101824
- Sacks FM, Bray GA, Carey VJ, et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med. 2009;360(9):859–873. doi:10.1056/NEJMoa0804748
- Thomson, C. A., Stopeck, A. T., Bea, J. W., Cussler, E., Nardi, E., Frey, G., & Thompson, P. A. (2010). Changes in body weight and metabolic indexes in overweight breast cancer survivors enrolled in a randomized trial of low-fat vs. reduced carbohydrate diets. Nutrition and Cancer, 62(8), 1142–1152. https://doi.org/10.1080/01635581.2010.513803
- Naude CE, Schoonees A, Senekal M, Young T, Garner P, Volmink J. Low carbohydrate versus isoenergetic balanced diets for reducing weight and cardiovascular risk: a systematic review and meta-analysis [published correction appears in PLoS One. 2018 Jul 2;13(7):e0200284]. PLoS One. 2014;9(7):e100652. Published 2014 Jul 9. doi:10.1371/journal.pone.0100652
- Zajac A, Poprzecki S, Maszczyk A, Czuba M, Michalczyk M, Zydek G. The effects of a ketogenic diet on exercise metabolism and physical performance in off-road cyclists. Nutrients. 2014;6(7):2493–2508. Published 2014 Jun 27. doi:10.3390/nu6072493
- Lima-Silva, A. E., Pires, F. O., Bertuzzi, R., Silva-Cavalcante, M. D., Oliveira, R. S. F., Kiss, M. A., & Bishop, D. (2013). Effects of a low- or a high-carbohydrate diet on performance, energy system contribution, and metabolic responses during supramaximal exercise. Applied Physiology, Nutrition, and Metabolism = Physiologie Appliquee, Nutrition et Metabolisme, 38(9), 928–934. https://doi.org/10.1139/apnm-2012-0467
- Phinney SD. Ketogenic diets and physical performance. Nutr Metab (Lond). 2004;1(1):2. Published 2004 Aug 17. doi:10.1186/1743-7075-1-2
