The ketogenic diet is one of the hottest diet trends at the moment. Not fat-adapted yet? Not putting sticks of butter in your coffee? Welp, you can not sit with us! (A sarcastic reference to Mean Girls, in case you missed it.)
Jokes aside. I do not know what's more disturbing – putting sticks of butter in coffee or the fact that I memorized a line of mean girls.
, the keto diet is not anything new. In fact, it's been around for a century and it's commonly used in the treatment of epilepsy (1). Classified as a very-low-carbohydrate, ultra-high-fat diet, it involves the manipulation of macronutrients to induce a metabolic state called ketosis, a consequence of the varnish of carbs.
The generic macronutrient makeup of the keto diet is About 60-80% of total energy intake (calories) derived from fat, about 20% from protein, and about 1
Recently, keto fans have peddled it as a superior method for improving body composition, purporting that the unique metabolic state – ketosis – outperforms any other diet.
Why It's Not Superior for Fat Loss
A 2006 landmark study by Johnstone et al. (KLC) and a non-ketogenic low carbohydrate diet (NLC) (3).
Twenty participants were randomly assigned to the KLC (60% of calories as fat, beginning with approximately 5% of calories as carbohydrates) or NLC (30% of calories as fat, approximately 40% of calories as carbohydrates) group. Protein intake was comparable (30% of calories) between the two diets, with the KLC group having a slightly higher intake (33%) than the NLC group (31%). (Table 1).
During the 6-week trial
Following the 6-week trial, the researchers found no significant difference in terms of total weight loss between both groups. Although not statistically significant, the NLC group actually lost more weight than the KLC group. Fat-free did not significantly change in both groups.
Moreover, there were no differences in resting energy expenditures or respiratory quotient between groups. The KLC diet, but, because blood ketones were directly related to LDL cholesterol concentrations and because of inflammatory risk, which was elevated with adherence to KLC diet, Severe restrictions in dietary carbohydrates are not warranted. "
The NLC had more than 67% of the recommended dietary intakes for micronutrients ; 67% of recommended dietary intakes (Table 1).
Nutrient Composition of the Ketogenic Low Carbohydrates (KLC) and Non Ketogenic Low Carbohydrates (NLC) Diets
|Nutrients||KLC Diet||NLC Diet|
|Energy [mJ (kcal)]||6.25 (1500)||6.25 (1500)|
|Carbohydrates [g (% of energy)]||33 * (9)||157 * (42)|
|Protein [g (% of energy)]||125 (33)||117 (33)|
|Fat [g (% of energy)] [Saturatedfat [g (% of energy)]||35 (21)||13 * (8)|
|] Monounsaturated fat [g (% of energy)]||34 (20)||16 (10)|
|Polyunsaturated fat [Cholesterol (mg)||620||230|
|Fiber [g (% of energy)]||14 (8)||7  (g)||15 *||30|
|Vitamin A (retinol equivalents)||860||1910|
|Niacin (mg) [VitaminB-6 (mg)||1.80||2.15|
|Vitamin C (mg)||100 [Order]||16.9. Vitamin E (mg) (alpha equivalents)||5.90 *||10.20|
|Folate (μg) *||440|
|Iron (mg)  10 * [1Magnesium (mg)||190 *||315|
|Potassium (mg)||1935 *||3535|
* Values ≤67% of daily recommendations for 31- 50-y-old women.
In addition, a more recent meta-analysis (a study of studies) by Aragon et al., Scrutinized the ketogenic diet's influence on body composition and found that as long as protein and calorie intake was matched between ketogenic and non-ketogenic diets (2).
Aragon and colleagues said, "To date, no controlled, inpatient isocaloric diet comparison fat loss or thermic advantage to the lower carbohydrate or ketogenic diet. "
Why It's Not Optimal for Hypertrophy
So the ketogenic diet fail ed to outperform any other fat loss, but what about building muscle?
To build muscle, a few criteria must be met. First, you must be in a caloric surplus – ingesting more calories than they're expending. Skeletal muscle tissue. This usually amounts to 0.7g to 1g of protein per pound of bodyweight (1.6 – 2.2g / kg). (3).
Lastly, and most importantly, the subjects must be resistant training. A keto dieter should easily be able to meet the aforementioned criteria, right?
Not so fast! During a recent 8-week study by Vargas et al., A non-ketogenic diet group (NCD) and a control group (4) were randomly assigned to a ketogenic diet group (KD). A hyper-caloric state of 39 calories per kilogram of body weight which is targeted in all subjects. Protein intake was matched at 2g / kg in both the diet and the non-keto diet group.
After eight weeks of supervised resistance training and diet intervention, body mass decreased significantly in the NKD group and decreased KD group, albeit not statistically significant.
Although a caloric surplus was targeted in all groups, the KD group failed to reach it. Why? Well, we can only assume by the decrease in fat mass observed in the KD group that the keto diet proved to be too powerful, as referenced by several studies (5).
In another study by Greene et al, researchers followed and elite weightlifters and powerlifters on ad libitum (unrestricted) conventional diet or ad libitum ketogenic diet over the course of three months (6).
Long-Term Leanness and Gains
Sure, once you reach ketosis and become fat, you'll start using fat as fuel; however, it does not circumvent the laws of thermodynamics – calories in / calories out.
And since calories are central to both weight loss and weight gain, you're better off choosing a dietary approach that's sustainable. Those looking to gain lean body mass are probably better off sticking to a non-ketogenic diet.
Keto – You're Doing It Wrong
What's The Best Diet For Losing Fat?
- Paoli, A., Rubini, A., Volek, J.S., & Grimaldi, K.A. (2013). Beyond weight loss: a review of the therapeutic uses of very low carbohydrate (ketogenic) diets. European journal of clinical nutrition, 67 (8), 789-96.
- Aragon, A.A., et al. (2017). International society of sports nutrition position: diets and body composition. Journal of the International Society of Sports Nutrition, 14, 16. doi: 10.1186 / s12970-017-0174-y
- Morton, R.W., et al. (2017). A systematic review, meta-analyzes and meta-regression of the effects of protein supplementation on immune-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine. doi: 10.1136 / bjsports-2017-097608
- Johnston, C.S., et al. (2006). Ketogenic low-carbohydrate diets have no metabolic advantage over non-ketogenic low-carbohydrate diets. The American Journal of Clinical Nutrition, Volume 83, Issue 5, May 1, 2006, Pages 1055-1061, http://doi.org/10.1093/ajcn/83.5.1055
- Gibson, A.A., et al. (2014). Do ketogenic diets really suppress appetite? A systematic review and meta-analysis. Obesity Reviews, 16: 64-76. doi: 10.1111 / obr.12230
- Green, D.A., et al. (2018). A low-carbohydrate ketogenic diet reduces body mass without compromising performance in powerlifting and Olympic weightlifting athletes. Journal of Strength and Conditioning Research, 1st doi: 10.1519 / jsc.0000000000002904