The Carnivore Diet - An Unbiased Review.

IN TODAY’S ISSUE
The Carnivore Diet

Good morning, with the rise in popularity of the Carnivore diet and having personally been asked my opinions on it, I have decided to tackle what seems to be a controversial subject.

The Carnivore Diet has went viral on social media, with influential people like Joe Rogan explaining its “benefits” on his podcast.

Here at Strength Framework, I do all the research, look at all the facts, break them down for you and present you with a non biased review. This issue will be longer than 5 minutes, sorry. There’s a lot to unpack.

Today’s Layout: 👇

• What Even Is The Carnivore Diet? 🥩

• What The Science Has To Say? 🔬

• Key Takeaways & Practical Applications 🤓

THE BRIEF
What Even Is The Carnivore Diet & Some Basics.

The Diet, is a zero carb elimination diet, which excludes plant based foods. It allows animal products only such as meat, fish, eggs and low lactose dairy. Comparisons can be drawn to the Keto diet which restricts carbs.

These Diets with the removal or reduction in carbs have claimed benefits such as weight loss, protection against disease, reduced inflammation, sustained energy levels throughout the day, enhanced mental clarity, clearer skin and increased testosterone.

The idea behind the Keto and Carnivore Diet is that by removing carbs you put your body in a state of “Nutritional Ketosis”. Essentially your body is starved of carbohydrates. As a result, glycogen stores are depleted, triggering a series of metabolic changes, gluconeogenesis and ketogenesis.

When the body is in a state of Ketogenesis, insulin secretion is low due to feedback from blood glucose levels, which leads to a decrease in the stimulation of fat and glucose storage. Fatty acids are then metabolized into Ketones, and serve as an alternative energy source for the body. This usually takes a few days to kick in.

With all the benefits mentioned above, it’s worth mentioning weight loss alone boosts all the same health markers (Ryan & Yockey, 2017).

Does anyone remember The Twinkie Diet? Well… An overweight nutrition professor at Kansas State University decided to carry out a case study on himself. He ate a twinkie every three hours while awake for two months and still lost lost 27 pounds. What’s not always mentioned is that he also consumed protein shakes, a multivitamin, and vegetables everyday. Even though a good portion of his diet was junk food, he still improved his “bad” LDL and “good” HDL cholesterol levels. (More on LDL and HDL Below).

Moral of the story above? We know weight loss happens through being in a calorie deficit, and reducing body fat results in improved overall health markers. Many people just unconsciously eat fewer calories when they are on a restrictive or elimination diet, which makes it much easier to lose weight.

Intermittent Fasting? Reduced eating window time. Carnivore? Less food options. You get the picture…

We also know that carbohydrates are the bodies main source of fuel and can improve performance in sports and the gym. When carbs are not available the body turns to other fuel sources, as stated above.

A Systematic Review and Meta Analysis by (King et al., 2022) which included 21 studies and 226 participants, found that Carbohydrate intake had a positive effect on resistance training by enhancing volume performance when sessions exceeded 45 min.

As I said, this in impartial. So what does the scientific evidence have to say on body composition, performance and overall health?

SCIENCE
What The Research Has To Say

The Harvard Carnivore Diet Study by (Lennerz et al., 2021) was a large self reported, social media survey involving 2029 participants who had been following the Carnivore Diet for over 6 months. Self reported adverse symptoms were under 1%. 95% reported health improvements and the authors state “Participants with diabetes reported benefits including reductions in median [IQR] BMI (4.3 [1.4–7.2]), glycated hemoglobin (0.4% [0%–1.7%]), and diabetes medication use (84%–100%)”. The study also also had participants report their cholesterol levels, according to their survey results, LDL Cholesterol was elevated, and HDL Cholesterol was at optimal range.

Below is a chart from the study on self reported results on several factors.

Unfortunately the body of scientific evidence for the Carnivore Diet is limited as it is relatively new, which is why I have decided to draw on some research which has been done on the Keto Diet for reference with regards to very low carb intake and high fat intake.

A 3 month Pilot Study on Crossfit Trainees by (Kephart et al., 2018) investigated the effects of the Keto Diet on body composition and performance parameters, involving 12 participants (9 men & 3 woman). The results? DXA fat mass decreased by 12.4% in Keto Group however DXA total lean body mass changes were not different between groups suggesting the non Keto Group increased muscle mass. HDL “good” cholesterol, and triglycerides were similar between groups, although LDL “bad” cholesterol increased ~35% in Keto Group. 1RM back squat, 400m run time, and VO2 were similar between groups. Authors state: “Adopting a ketogenic diet causes marked reductions in whole-body adiposity while not impacting performance in recreationally-trained CrossFit trainees”.

A randomised control trial on Competitive Natural BodyBuilders by (Paoli et al., 2021) had 19 volunteers follow either a Keto Diet or a standard western diet for 8 weeks. Body fat significantly decreased in Keto group, whilst lean mass increased significantly only in western diet group. Maximal strength increased similarly in both groups. Authors State: “The Keto Diet may be useful during bodybuilding preparation for health and cutting purposes but with the caution that hypertrophic muscle response could be blunted.”

A study published in the Journal of the International Society of Sports Nutrition by (Vargas-Molina et al., 2020) took 21 strength trained woman and split them into a Keto Diet (KD) or Non Keto Diet (NKD) group to assess the effects on body composition and strength. Results? A significant reduction in fat mass was observed in KD not in the NKD Group. Fat Free Mass remained unchanged in the KD group but showed a slight increase in the NKD group. (Fat Free Mass accounts body mass excluding fat, ie. Muscle). In terms of strength, the NKD group out performed the KD in all tests. As you can see from the figure below from the study, differences in bench strength was moderate and squat was significant, favoring the NKD Group.

In contrast to the study above, a randomised control trial published in the journal of strength & conditioning by (Wilson et al., 2020) looked at the effects of a Keto Diet on body composition, strength, power and hormonal profiles of 25 men over an 11 week period. Two Groups, one Keto and the other followed a standard western diet. Lean Body Mass increased by 2.4% and 4.4% in favour of the western diet group. Fat Mass decreased in both (-2.2 vs -1.5) in favour of the Keto Group. While Strength & Power increased to the same extent between groups. Total testosterone increased 118 ng·dl vs -36 ng·dl in favour of the Keto Diet.

SHORT CUT ANSWERS
✍️ Key Takeaways & Practical Applications

• Although the Carnivore & Keto Diet are similar, the Keto Diet allows for under 50g of carbs per day and inclusion of veg etc. Whereas the Carnivore Diet calls for elimination of these foods and all carbs.

• The Harvard Carnivor Study was a self reported survey and not done under clinical settings. Under 1% of participants reported adverse side effects and 95% reported health improvements.

• The rise in LDL Cholesterol (bad) reported in 2 studies should be highlighted and something to be considered. As always a healthcare professional should always be consulted.

• All studies showed favour to the High Fat / Low Carb groups in terms of fat mass reduction.

• The trend of the evidence shows favour to a standard diet in terms of lean body mass (muscle size).

• Evidence is somewhat split in terms of strength and performance between diet protocols.

• Diet protocols which remove carbohydrate intake may negatively impact performance in the gym where sessions last longer than 45 minutes or volumes over 10-12 sets per session.

I have no skin in the game as they say. I don’t care what diet protocol you choose to follow. I just want to present you with the evidence available to help you make informed choices instead of just opinions you see on TikTok.

Any diet you choose to follow should be sustainable and relatively enjoyable.

If you goal is fat loss, high fat low carb diets such as the Carnivore and Keto diets can be a viable option and if this style of eating suits you and your lifestyle, great! However they are not the only option. A calorie deficit is what your after.

If your goal is to build muscle, including carbs in your diet may be more optimal in agreement with the trend of scientific literature.

As I have stated the research done on the Carnivore Diet is currently limited and with the Harvard study not being done in Clinical settings, the results shouldn’t be taken as hard facts.

With the potential for elevated LDL cholesterol, your doctor or health care professional should always be consulted before starting or changing your diet.

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