If you've been training for a while, chances are you've heard of the ketogenic diet.
Whilst it has benefits, is it really the best way to lose weight?
You must weigh up this eating approach to see if it's the best decision for you.
So allow me to break it down for you to make this decision easy!
THE KETOGENIC DIET AND KETOSIS
The ketogenic diet involves lowering your carbohydrates extreamly low, putting your fats high and keeping protein adequate, to the point where your body is in a state of what's called ketosis.
This is when you burn fats as opposed to carbohydrates for energy.
When we eat carbohydrates, the glucose is used to fuel the body and our brain. But when we aren't getting adequate carbohydrates (such as in the ketogenic diet) fats are broken down into glucose instead.
This is called gluconeogenesis (neo is greek for "new" and "genesis" means to make).
IS THE KETOGENIC DIET BETTER FOR MUSCLE GROWTH AND FAT LOSS?
There's some good research into this, including this study (1) that looked at 20 overweight people for 6 weeks on either a ketogenic diet or a moderate carb (non-keto) diet.
Both diets had 1500 calories, and the subjects did no exercise.
The ketogenic diet consisted of:
PROTEIN: 125
CARBS: 33
FAT: 100
The moderate carb diet was:
PROTEIN: 117
CARBS: 157
FAT: 50
And what did they find?
No significant differences in fat loss. There was no significant difference in fat free mass either.
Furthermore, hunger ratings were better for both diets, with no differences found there either. Also, insulin sensitivity was bolsted for both diets, with no differences between them.
However, recent research has found to the contrary (2).
In this study, 26 college aged resistance trained men were divided into a ketogenic diet (Pro=20 Fat=20 Carb=5) or a tradtional western diet (Pro=20 Fat=25% Carb=55%).
These subjects were performing a periodised weight lifting program three times a week.
Measurements were taken at week 0 and 11.
And what did they discover?
The ketogenic diet group had a 4.3kg increase in lean body mass whilst the western diet group experienced a 2.2kg increase.
This study had a carb up at the end, so this was why ultimately amongst scientific circles, it was accepted it was no better for muscle growth.
Further to this study; the ketogenic diet group lost 2.2 kg vs 1.5kg in the traditional diet. But as we know, water weight is most likely responsible here.
The researchers are careful with their conclusion:
"These results indicate that the very low carbohydrate ketogenic diet may have more favorable changes in lean body mass, muscle mass, and body fatness as compared to a traditional western diet in resistance trained males."
Note the word "may!"
What I've just presented is some of the better research into the benefits of the diet, but I'm afraid currently the negative effects for muscle growth should outweight the desire for anyone to go on it - this link here explains how a high fat diet can interfere with muscle signalling.
So that's both sides of the data - and I have to say, with there being no differences in fat loss and the fact that muscle signalling may be hindered on a ketogenic approach - I'm not a supporter of the diet at all, based on the data.
KETOGENIC DIET AND STRENGTH
What this study also found was a non-significant increase in strength for both groups - so you won't get any stronger on a ketogenic diet.
But this is where things get interesting; the western diet subjects were massively bolstered in the wingate test; a tough anaerobic test on a stationary bike.
This was obviously because they had more stored GLYCOGEN - that is, more stored carbohydrate than those on the ketogenic diet.
And this is where I must make this point: If you're a really active person, eg, soccer/football on the weekends, and weight lifting during the week, then the ketogenic diet is NOT for you. You need the glycogen storage.
But if you're primarly a resistance trainer then you can get away with a ketogenic diet for life - if indeed you can stick to it.
As I've told you before you don't need carbs after training as replenising glycogen for a bodybuilder is quite a simple task.
A resistance trainer doesn't lose as much glycogen as a distance runner.
You have what's known as glucose transporter type 4 (otherwise known as GLUT4) which ensures the uptake of glucose in the absence of insulin.
This means a whole heap of carbs aren't vital for glycogen replenishment - as during glycogen depletion there's much done by GLUT4. (3).
Other research however has found that if protein numbers are on point - then either your distribution of fat or carbs isn't really that important; no one macronutrient distribution was found to be superior for fat loss in this case (4).
Although there is no nutrional need for carbohydrates by human beings (5) we have still come to LOVE them and there's no harm in enjoying them.
Furthermore - we really do LOOK better with them - as glycogen pulls in water into our muscles making them look BIGGER.
There's a reason bodybuilders carb up before shows, and we all want to look our best, right?
I can spot a ketogenic bodybuilder a mile away, they look stringy and improve significantly with a few more carbs to fill out their muscles.
So if you're super active or you feel dreadful (like me) on very low carbs, then forget all about the ketogenic diet!
But if you can handle it and you have a desk job and only lift weights and don't do any cardio, then there's no harm in taking to a ketogenic diet.
THE PALEO DIET FOR FAT LOSS
Well you all know my thoughts here, you can find my paleo article on this website!
However, a paleo diet is a spin off of a ketogenic diet - except it omits coffee, alcohol and grains completely (you could still possibly fit in a slice of bread under a ketogenic diet).
The paleo diet also suggests it is superior for health - a claim which has no scientific evidence.
The diet is completely based on false assumptions that have been scientifically disproven in the context of the caveman and his health.
At best, some paleo fanatics point to some results from the ketogenic diet, which is completely WRONG.
Whilst they are similiar, they are not the same; the ketogenic diet doesn't omit certain foods with a bogus scientific backing, it merely just limits carbohydrate intake.
Anyone promoting the paleo diet is most likely trying to sell you a product - forget about those people.
Put simply, there's no superior benefit to a paleo diet. In fact, there is no room for it anywhere, at all.
IIFYM
Also referred to as flexible dieting, in my opinion, this approach (I fall short of calling it a "diet" because it isn't) I feel is the most effective way of losing weight without losing your mind.
It ensures you hit your required fibre intake whilst hitting your protein, fat and carb numbers, from the sources of food you like best.
This may be white bread, or brown rice, etc.
This leaves room for a little treat daily, to ensure cravings don't pile up to the point a binge gets the better of you and puts you back.
A flexible dieting approach has been found to prevent overeating and poor moods whilst dieting (6).
Here's what this study concluded:
"The strongest canonical correlation was the relationship between flexible dieting and the absence of overeating, lower body mass and lower levels of depression and anxiety."
This is why I continue to provide tailor made diet plans for FIT'N'FLEXED weight loss customers and continue to deliver great results - it's all about preventing overeating, eating what you love, and being happy...all geared towards you!
We can conclude that a ketogenic diet is still very beneficial if you can stick to it.
But the point is, it isn't vital, and is not a superior option for the majority of the population.
If you're keen to try it then do so, and if you prefer it - then go nuts!
But if you're a very active person it won't be your best bet.
A good idea (providing you were up to it) would be to try both for an extended period, monitor your strength, body composition and mood.
Then my friend, you've got your own personal data to draw from, unique only to YOU!
"Stay Fit, Stay Flexed!"
REFERENCES
(1) Johnston CS et al. Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets. Am J Clin Nutr May 2006 vol. 83 no. 5 1055-1061
(2) Wilson JM et al. The effects of ketogenic diet on strength and power. Presented at the Eleventh International Society of Sports Nutrition (ISSN) Conference and Expo.
(3) Derave W, Lund S, Holman GD, Wojtaszewski J, Pedersen O, Richter EA: Contraction-stimulated muscle glucose transport and GLUT-4 surface content are dependent on glycogen content. Am J Physiol 1999, 277(6 Pt 1):E1103-10.
(4) Noakes M. Comparison of isocaloric very low carbohydrate/high saturated fat and high carbohydrate/low saturated fat diets on body composition and cardiovascular risk. Nutr Metab (Lond). 2006; 3: 7. Published online 2006 Jan 11.
(5) Westman E. Is dietary carbohydrate essential for human nutrition. Am J Clin Nutr May 2002 vol. 75 no. 5 951-953.
(6) Smith CF, Williamson DA, Bray GA, Ryan DH. Flexible vs. Rigid dieting strategies: relationship with adverse behavioral outcomes. Appetite. 1999 Jun;32(3):295-305.
Author
Dayne Hudson