This is a 3 hour 'live stream', with with the skill and ease of a drunk burnout who is barely hanging onto their AV club membership.

It doesn't really get started until 30m. It is fascinating, everyone was operating in good faith.

They did try to do zero carb, but they couldn't quite do it, so they still had 12% carbs every day - so this is a meat based low carb. This works out to about 100g of carbs per day, which probably kept them out of ketosis.

28 days is just about long enough to adapt to a new diet, but the results should only be of interest they would need more time to stabilize.

The vegan stayed vegan, and the carnivore stayed carnivore after.

::: spoiler summerizer Low-carb vs plant-based swap setup

• The 28-day diet swap moved Vegan->LowCarb from a 10-year vegan/plant-based diet to a mostly animal-food low-carb diet, and Carnivore->Vegan from a 90-95% carnivore diet to a whole-food plant-based diet.
• The bloodwork stayed hidden from Vegan->LowCarb, Carnivore->Vegan, and Drew until Dave Feldman reviewed it live, and Dave also gathered input from four doctors with low-carb vegan, protein-centered, carnivore, and Mediterranean perspectives.
• Vegan->LowCarb's intervention was not a strict carnivore or ketogenic protocol because his macro split was about 58% fat, 30% protein, and 12% carbohydrate, with dairy and some non-animal foods entering the diet.
• Carnivore->Vegan's intervention used a typical whole-food plant-based pattern: fruit and nut butter, beans, rice, sweet potatoes, stir-fries, and two meals per day with coffee in the morning.
• The comparison has limits because the men differ by roughly 14 years, Carnivore->Vegan had recently lost about 100 pounds after being 120 pounds overweight, and neither diet was fully locked down by a meal plan.

Subjective outcomes

• Carnivore->Vegan's vegan month ended with low energy, workday naps, increased hunger, no satiation, worse digestion, major gas and bloating, skin issues showing up, and about 10-12 pounds of weight gain.
• Carnivore->Vegan felt normal again after returning to meat, could work a long shift without a crash, and saw no major digestive readaptation problem.
• Vegan->LowCarb began the animal-food month with a smooth transition, then had meals that left him down for 30 minutes to several hours, fatigue, slower thinking, brain-fog-like symptoms, and worse sleep.
• Vegan->LowCarb liked the steady lack of sugar high/crash and almost no gas, but he missed quick carb energy and returned to plant-based eating after the experiment.
• Vegan->LowCarb gained about 4 pounds after reintroducing plant foods, and Dave interpreted much of that short-term change as glycogen and water rather than new muscle or fat.
• Dave pushed back on judging face photos, because lighting, grooming, timing, hydration, sleep, and confirmation bias can make visual comparisons unreliable.

CBC, thyroid, vitamins, methylation

• Vegan->LowCarb's comprehensive metabolic panel was mostly quiet, but BUN rose to 23, BUN/creatinine rose from 11 to 24, and AST dropped to 13.
• Carnivore->Vegan's comprehensive metabolic panel was also mostly quiet, with glucose roughly stable, BUN lower near the bottom of range, a mildly high albumin/globulin ratio that drew little concern, and AST/ALT still low despite small rises.
• Vegan->LowCarb's RBC and hemoglobin ended slightly below range, and RDW improved only slightly toward the 12.5 target raised by doctor three.
• Carnivore->Vegan's RDW remained above the 12.5 target and improved modestly during the plant-based period.
• Doctor one raised thyroid concern for Vegan->LowCarb, recommended thyroid antibodies, wanted TSH near 2, and said thyroid replacement therapy might become relevant after medical follow-up.
• Vegan->LowCarb's B12 rose from 404 to 647 on the animal-food diet, while Carnivore->Vegan's B12 dropped from 439 to 321 on the plant-based diet.
• Both men had vitamin D concerns, with Carnivore->Vegan at 32.9 despite carnivore and night-shift work offered as one explanation.
• Doctors one, three, and four flagged folate and homocysteine concerns for both men and wanted MTHFR or methylation-pathway follow-up.
• The carnivore doctor viewed both men as likely too muscle-meat-heavy and not nose-to-tail enough, with possible riboflavin and folate issues.

Insulin, hormones, inflammation

• Vegan->LowCarb started with excellent fasting insulin at 2.9, but it rose to about 5 on the low-carb intervention; Dave still placed it in a good zone but wanted repeat testing because insulin can be pulsatile.
• Vegan->LowCarb's C-peptide also moved with the insulin rise, cortisol went down, testosterone went up, IGF-1 rose from 167 to 203, and homocysteine stayed high around 14 to 13.
• Carnivore->Vegan's fasting insulin improved from 4.4 to 2.1 on the plant-based intervention, which surprised Dave because Carnivore->Vegan also gained weight and lost energy.
• Doctor four had predicted Carnivore->Vegan would gain weight, drop insulin, lower metabolic rate, and dislike the plant-based intervention.
• Carnivore->Vegan's cortisol fell to 4.4 AM, the lowest Dave had seen in his own lab review experience.
• Carnivore->Vegan's IGF-1 fell from 202 to 156, and his homocysteine stayed very high at 17.9.
• Carnivore->Vegan's C-reactive protein moved from 5.1 to 1.11 on plant-based; Dave used the first result as a marker needing repeat testing after rest, low stress, no hard exercise, and better sleep.
• Dave's own CRP data showed large exercise-driven spikes, including 52.96 after a half marathon and 32.44 after a full marathon, while his baseline values were usually under 1.
• Dave's read was that CRP, fasting insulin, and lipids are his "big three" lab areas, and the doctors focused more on nutrient and endocrine flags.

Lipids and particle markers

• Vegan->LowCarb's lipid shift matched Dave's lipid-energy expectation: total cholesterol rose from 147 to 207, LDL rose from 47 to 119, HDL rose from 68 to 77, and triglycerides stayed excellent at 66 to 61.
• Vegan->LowCarb's LDL-P rose from 322 to 1128, roughly concordant with LDL-C, HDL-P rose from low range, small LDL-P stayed under 90, and LP-IR stayed under 25.
• Carnivore->Vegan's total cholesterol dropped from 222 to 149, LDL dropped from 156 to 82, HDL rose from 47, and triglycerides unexpectedly fell from 94 to 60 on the plant-based intervention.
• Carnivore->Vegan's LDL-P moved down with LDL-C, small LDL-P was 831 on the carnivore side, and LP-IR worsened from under 25 to 41 on plant-based.
• Carnivore->Vegan's lipoprotein(a) moved from 37 to 22 and LP-PLA2 activity followed the lipoprotein movement, which Dave saw as exciting for lipid-pattern tracking.
• Dave said that if he only had the labs and no subjective experience, the plant-based side looked better overall in this swap because of Carnivore->Vegan's CRP, insulin, triglycerides, and LDL movement.

Experiment reading and next design

• The lab winner was not the lived-experience winner, because both men disliked the swapped diet and both wanted to return to their original way of eating.
• Drew accepted that the plant-based labs came out slightly better in this test, especially triglyceride-to-HDL ratio, while still rejecting the idea that veganism was better in general.
• Dave said both lab sets contained a lot of good news, because most CMP and CBC markers did not draw attention and both men showed metabolic flexibility.
• The biggest practical gaps were missing food control, meal plans, blood pressure, DEXA scans, daily beta-hydroxybutyrate, free fatty acids, basal metabolic rate, and higher-frequency lab draws.
• Dave wanted future experiments to define allowed foods and macro targets in advance, use tighter animal-food and plant-based plans, and collect enough repeated measures to see transitions over time.
• Vegan->LowCarb said he would have benefited from simple prescriptive rules, such as a target amount of meat, organ meat, and fat, because tracking macros without coaching left him unsure.
• Gut microbiome testing came up as an unresolved but interesting future layer, because Dave wanted more controlled and higher-frequency testing than he had seen.
• Drew floated a future round with people already involved in health content, possibly with a whole-food plant-based chef creating a meal plan.
• The ending lesson is that this first run produced useful bloodwork and useful lived feedback, but the next run needs stricter design before it can answer harder vegan-versus-carnivore questions.

References

• [01:03] Cholesterol Code — https://cholesterolcode.com/
• [01:03] The Lipid Energy Model: Reimagining Lipoprotein Function in the Context of Carbohydrate-Restricted Diets — https://doi.org/10.3390/metabo12050460
• [01:03] White Bread and Processed Meat Experiment — https://cholesterolcode.com/the-tandem-drop-experiment-part-2-carbs/
• [01:16] An interpretable machine learning model of biological age — https://doi.org/10.12688/f1000research.17555.1
• [01:18] Red Blood Cell Distribution Width and Mortality Risk in a Community-Based Prospective Cohort — https://doi.org/10.1001/archinternmed.2009.55
• [01:34] Who Gets 67 C-Reactive Protein Tests? I do! — https://cholesterolcode.com/who-gets-67-c-reactive-protein-tests-i-do/
• [01:54] A Provocative Question About Cholesterol and Mortality — https://cholesterolcode.com/a-provocative-question-about-cholesterol-and-mortality/
• [01:59] Elevated LDL Cholesterol with a Carbohydrate-Restricted Diet: Evidence for a "Lean Mass Hyper-Responder" Phenotype — https://doi.org/10.1093/cdn/nzab144 :::