The mirror tells only part of the story
Some fat sits just under the skin. Some sits deeper, around organs in the belly. This deeper fat is called visceral fat.
It matters because it is linked with health problems such as type 2 diabetes. In a follow-up of two diet trials, people who had lost more visceral fat later had a lower risk of diabetes. That is a useful finding, though it does not tell us that one diet prevents the disease. [1]
Weight alone cannot tell the whole story. Waist size can help show risk, but a home scale's “visceral fat” number is an estimate—not a picture of the fat inside you. [2–4]
Old foods, different modern approaches
Fermentation is an old way to keep food and change its taste. Yogurt and fermented vegetables are familiar examples. People used these methods long before today's diet names. [12]
Today's traditional-food movements draw on different parts of that history. The Weston A. Price Foundation highlights traditional foods, including animal and fermented foods; GAPS, a separate modern protocol, includes meat stock and fermented foods. Their self-descriptions offer context, not clinical evidence. [24, 25]
This overlap helps explain the appeal of modern meat-and-ferment patterns to some traditional-food and functional-health audiences.
Dr. Sean O'Mara's Living Diet is one current example. Reporting describes meat and fermented foods in a low-carb pattern, with a focus on visceral fat. [5, 23, 27]
What's reported to be on the plate?
Reported food pattern—not a prescription or an official rulebook
- Grass-fed meat, mentioned in the accessible Wall Street Journal article summary. [27]
- Fermented vegetables, such as sauerkraut, described as a daily garnish in Business Insider coverage. [23]
- High-protein, low-carb eating, with advice to avoid sugary treats, alcohol and junk food. [23]
Press reports mention yogurt and kefir, but a complete published list of O'Mara's food rules could not be verified from the sources reviewed. [23]
What looks promising?
Low-carb eating can help—but it is not the only route
Evidence: human diet studies
Some studies support low-carb eating for visceral-fat loss. In the final DIETFITS analysis, the low-carb group lost more estimated visceral fat than the low-fat group at both six and 12 months; the gap between groups was larger at six months. That study did not test the Living Diet. [6]
Other studies show why the details matter: greater total-fat loss can help explain the result, and exercise can make its own contribution. [7, 8]
A plant-rich route also deserves attention. In DIRECT-PLUS, a green-Mediterranean pattern with more plant foods and less red and processed meat reduced visceral fat more than the comparison diets. [9]
The fair conclusion: Low-carb eating has useful evidence. So do plant-rich patterns. Those findings do not establish meat plus ferments as the best combination.
Study details: what was measured, and what changed?
- DIETFITS: The trial randomized 609 adults; this analysis used data from 449. Healthy low-carb produced 10.6 cm² greater loss of DXA-estimated visceral fat than healthy low-fat at six months (95% confidence interval 5–16.2), and 6.3 cm² greater loss at 12 months (95% confidence interval 0.6–12). DXA is an X-ray-based estimate, not MRI measurement. Both differences were statistically significant in the final indexed abstract. The comparison of visceral-fat loss relative to fat under the skin favored low-carb only at six months. The final indexed abstract, not the earlier conference estimate, is used here. [6]
- Goss: An eight-week MRI study analyzed 34 older adults with obesity. Very-low-carb produced more visceral-fat loss, but also more weight and total-fat loss. After adjustment for total-fat loss, its visceral-fat advantage was no longer statistically significant. [7]
- CENTRAL: In an 18-month MRI trial of 278 adults, Mediterranean/low-carb improved selected liver, heart-region and pancreatic fat deposits. Added exercise independently helped visceral-fat loss. Those organ-fat results are not all the same as abdominal visceral-fat loss, and the trial does not establish that sprinting beats other exercise. [8]
- DIRECT-PLUS: Among 294 adults, the green-Mediterranean group had greater MRI-assessed visceral-fat reduction. All groups received activity guidance. Several food changes were bundled together, so the result cannot be assigned to one food. [9]
The reviewed sources did not identify a controlled outcome trial of the named Living Diet. This is a finding from the search, not proof that no study exists.
Fermented foods can change gut microbes
Evidence: early human research
In a small Stanford study, adults who increased fermented foods gained more variety in their gut microbes. Several blood proteins linked with inflammation also fell. [10]
That is promising. The study looked at microbes and immune markers—not whether people lost visceral fat or avoided disease.
Could ferments fit well with keto? That is an interesting question. Another study found that keto changed gut microbes, including a drop in one bacterial group. It did not test whether adding yogurt or kefir reversed that change. [11]
Ferment study details and the keto question
Wastyk's study analyzed 18 adults per group. It compared high-fermented-food and high-fiber diets, with a four-week build-up and six-week maintenance period after baseline. The ferment group reached about six servings per day on average. That is study intake, not a daily target for everyone. There was no unchanged-diet control group. [10]
Ang's study examined keto-related microbiome changes in 17 men. A decline in Bifidobacterium does not by itself show a damaged microbiome. The immune-cell experiments included mice, and no keto-plus-ferments restoration treatment was tested. [11]
Three words that mean different things
| Word | What it means |
|---|---|
| Fermented | Microbes helped change the food. They may no longer be alive in the finished food. |
| Live cultures | Living microbes are present. That alone does not show a health benefit. |
| Probiotic | Specific live microbes, in a useful amount, have evidence of a health benefit. |
Milk can be pasteurized before yogurt cultures are added. Heat treatment after culturing is different. Check the label and handling instructions; refrigeration alone does not guarantee live cultures or a proven benefit. [12, 13]
Why practitioners may read LDL differently
A proposed explanation—not a safety finding
Some low-carb researchers propose that using more fat for fuel changes how the body moves fat through the blood. Their “Lipid Energy Model” may help explain why LDL cholesterol can rise while other blood-fat markers change. This is one research explanation, not a verified statement of O'Mara's personal views. [26]
Understanding why LDL rises is different from knowing whether the rise is safe. Strong evidence shows that long-term exposure to LDL-containing particles helps cause artery disease. ApoB can help assess the number of these particles. A smaller waist does not cancel that risk. [14]
Discuss cholesterol changes with your clinician, including whether an ApoB test would help. Do not dismiss a rise because you feel better, or stop prescribed treatment because of a diet story.
More on the LDL hypothesis and long-term safety
The Lipid Energy Model proposes increased fat transport and turnover during carbohydrate restriction. It seeks to explain a pattern that can include rising LDL and HDL with falling triglycerides. It is a mechanism hypothesis, not evidence that high LDL or ApoB is harmless. No cardiovascular-safety exception is established here. [26]
A small ketogenic feeding trial in healthy young women found increases in LDL cholesterol and ApoB. Long-term controlled evidence for meat-heavy patterns remains limited. [15, 17]
Traditional butter is not shown to be heart-protective just because it is traditional. A butter/plant-oil cohort reported mortality associations, but it was observational—not a trial of butter inside the Living Diet. [16]
A few safety checks matter
- Raw dairy: Raw milk can carry harmful bacteria. Pasteurized dairy is the safer choice, especially in pregnancy, childhood, older age or with a weak immune system. Fermentation is not a safety guarantee. [18, 19]
- MAOI medicines: Some MAOI medicines require limits on tyramine-rich foods, including certain aged or fermented products. Advice varies by medicine and dose; ask a pharmacist about your exact drug and food. [20]
- SGLT2 diabetes medicines: A keto diet can trigger ketoacidosis, a dangerous acid buildup, even without very high blood sugar. Discuss ketogenic plans with the prescriber first; do not change the medicine yourself. [21]
- Kidney disease: A high-protein plan may conflict with kidney care. Needs differ by disease stage, nutrition and dialysis status. [22]
Also consider fiber, food variety and tolerance before removing whole food groups.
Make the Human Signal connection useful
The Human Signal helps organize questions about food, gut symptoms, movement, sleep and daily habits. Here, its role is to connect observations—not diagnose a problem or choose a diet for you.
For example, if you notice symptoms after a fermented food, note the food, amount, timing and symptoms. That can make a conversation about tolerance more specific. It does not establish a gut imbalance.
Waist trends, activity, sleep and clinician-interpreted test results can add context. A scale score is one estimate, not the final answer. [2–4]
Home measurements: useful context, not a scan
Many scales use a small electrical signal and a model to estimate body composition. One device-specific study found poor agreement with CT assessment of visceral fat; that does not mean every model performs the same. [3]
Water balance, meals and exercise can affect readings. Similar measurement conditions reduce some noise but do not prove that a changing score tracks visceral-fat change. Waist-to-height ratio can help screen for risk in appropriate adults; it is not a direct fat measurement. MRI and CT are research reference methods, not routine scans everyone needs. [2–4]
The takeaway
This is a food pattern worth understanding, not a proven shortcut. Low-carb eating and fermented foods each have findings worth discussing. The next useful questions are: What changes for you? How can you measure it? And what needs watching for safety?
Sources
Evidence labels describe the support for a claim, not an independent clinical-review grade. Press reports describe the pattern; movement websites describe their own approach; neither establishes clinical benefit.
- Long-term MRI follow-up of CENTRAL and DIRECT-PLUS (2026). Original paper. Association after trials, not randomized proof of diabetes prevention.
- NICE: assessing central adiposity. Official guidance.
- BIA versus CT visceral-fat validation (2021). Original study. Device-specific, cross-sectional—not validation of change tracking.
- BIA instruments and clinical assessment (2025). Review.
- Official Living Diet episode page. Episode description. Topic provenance only; no timestamped quotations used.
- Follis et al., final DIETFITS analysis. Final publication record · DOI. Final abstract verified via EuropePMC; journal full text unavailable in the saved review. Superseded conference estimate not used.
- Goss et al. (2020). Original MRI trial. Total-fat adjustment retained.
- CENTRAL (2017 online/2018 print). Original MRI trial. Organ-fat and exercise/visceral-fat findings distinguished.
- DIRECT-PLUS (2022). Original trial. Bundled diet changes plus activity guidance.
- Wastyk et al., Cell (2021). Full primary paper. Microbe/immune endpoints, not visceral-fat or disease outcomes.
- Ang et al., Cell (2020). Full primary paper. Human microbiome changes distinguished from mouse immune experiments.
- Fermented Foods as a Dietary Source of Live Organisms (2018). Review. Fermentation history and organism viability.
- U.S. yogurt standard, 21 CFR 131.200. Regulation.
- European Atherosclerosis Society LDL consensus (2017). Evidence review.
- Burén et al., ketogenic feeding trial (2021). Full primary paper. No effect size used.
- Zhang et al., butter/plant-oil cohort (2025). Full primary paper. Prospective observational cohort; reported associations, not causal effects or a trial of the Living Diet. No numerical effect size used.
- Carnivore Diet scoping review (2026). Full review. Limited studies do not establish long-term safety.
- FDA raw-milk guidance. Current official guidance. Supports pathogen risk and pasteurized choices, including for higher-risk groups.
- CDC pregnancy food safety. Current official guidance. Distinguishes raw from pasteurized dairy and gives pregnancy-specific food guidance.
- MAOI tyramine guidance and official labels. Full review · phenelzine label · tranylcypromine label · selegiline label. Complete review and official drug labeling checked; restrictions vary by drug and dose.
- FDA Synjardy/Synjardy XR current labels (2026). Synjardy label · Synjardy XR label. Ketogenic diet is listed as a ketoacidosis precipitating condition and glucose may not be markedly elevated.
- KDIGO 2024 CKD guideline (current global standard confirmed). Official guideline page · full guideline PDF. Adapted to CKD stage and individual needs.
- Business Insider Africa, reported O'Mara food pattern (2026). Accessible report. Description, not outcome evidence or a definitive menu.
- GAPS official overview. Primary self-description. Used only for foods/context, not its clinical claims.
- Weston A. Price Foundation overview. Primary self-description. Movement context, not efficacy evidence.
- Norwitz et al., The Lipid Energy Model (2022). Primary hypothesis paper. Mechanism hypothesis, not cardiovascular-safety evidence.
- Wall Street Journal food-pattern coverage (2026). Original report. Only headline, deck and introductory paragraphs were accessible; these support the broad meat/ferments description, not a detailed menu.