Ultra‑Processed‑Smart Keto in November 2025: The New Cancer‑Precursory Evidence—and a Whole‑Food Keto Playbook You Can Use Today

Why this matters now

Ultra‑processed foods have been tied to broad cardiometabolic harms in recent scientific advisories and reviews. This month’s JAMA Oncology paper adds a cancer‑precursor signal in younger women, aligning with public‑health advisories that call UPFs a “growing public health challenge.” ^[3]

“Reducing ultra‑processed foods may help curb the rising burden of early‑onset colorectal cancer.” — Andrew T. Chan, MD, senior author (study press release). ^[4]

Large overviews likewise associate high UPF intake with higher risks of hypertension, cardiovascular events, digestive diseases, and all‑cause mortality, strengthening the case for a whole‑food approach on any diet pattern, including keto. ^[5]

What’s proven vs. what’s anecdotal

The Whole‑Food Keto Playbook (UPF‑Smart)

1) Set evidence‑based targets

• Net carbs: 20–50 g/day (personalize to maintain nutritional ketosis: β‑hydroxybutyrate ≥0.5 mmol/L).
• Protein: 1.2–1.6 g/kg reference body weight/day to protect lean mass, satiety, and metabolic health.
• Fat: to appetite—prioritize minimally processed sources (olive oil, avocado, nuts, eggs, fish).
• Fiber: aim 20–30 g/day using low‑carb vegetables, seeds, nuts, and psyllium; fiber supports colon and cardiometabolic health even on keto.

2) Make UPF‑smart swaps

• Keto “bread” (industrial) → flax‑chia skillet bread (home‑made: ground seeds, eggs, olive oil, baking powder).
• Keto snack packs → olives, cheese, nuts, hard‑boiled eggs, celery with almond butter.
• Keto desserts → 85% dark chocolate, cottage cheese with cinnamon, chia pudding with almond milk.

3) Build your plate (Whole‑Food Keto Pyramid)

• Base: non‑starchy veg (leafy greens, broccoli, cauliflower, zucchini, cabbage, mushrooms, peppers).
• Protein: fish/seafood, eggs, poultry, beef/pork (prefer minimally processed), tofu/tempeh if you include soy.
• Fats: extra‑virgin olive oil, avocado, olives, nuts/seeds; use butter/ghee sparingly if lipids run high.
• Flavor: herbs, spices, citrus, vinegars; avoid sugar‑heavy sauces and UPF condiments.

4) Electrolytes and blood pressure

• Early keto diuresis raises needs for sodium, potassium, magnesium. Use broth, mineral water, leafy greens, nuts/seeds, and salt mindfully.
• Consider potassium‑enriched salt substitutes if appropriate; WHO issued a 2025 guideline supporting lower‑sodium salt substitutes to reduce sodium exposure (avoid if contraindicated by CKD or meds). ^[12]
• Keep total sodium near general‑health targets unless advised otherwise; most adults benefit from limiting excess sodium per cardiology guidance. ^[13]

3‑Day Whole‑Food Keto Menu (anti‑UPF)

Two 15‑minute recipes

Smart supplementation (optional)

Safety: labs and follow‑up you shouldn’t skip

• Lipids: ApoB (first), LDL‑C, TG/HDL ratio at baseline and 6–12 weeks into keto; the Nov 2025 short‑term MKD study showed improved adiposity but an increase in atherogenic ratios—adjust fats (favor olive oil, nuts, fish; cut saturated fats) if ApoB rises. ^[14]
• Metabolic panel and electrolytes: check sodium/potassium/magnesium if symptomatic.
• GI health: emphasize low‑carb fiber from vegetables, seeds, and nuts; remember the adenoma signal is tied to UPFs, not to whole‑food keto. ^[15]
• Blood pressure: monitor at home; reduce sodium excess and consider lower‑sodium salt substitutes when appropriate. ^[16]

Common mistakes to avoid

• Relying on “keto” packaged foods (UPFs) instead of meat/seafood, eggs, veg, nuts, olives, and healthy oils. New November 2025 data reinforce this. ^[17]
• Undereating protein—risks lean‑mass loss and hunger.
• Skipping fiber—keto is compatible with high fiber via low‑carb plants and seeds.
• Ignoring labs—especially ApoB and TG/HDL—when transitioning to keto. ^[18]

Frequently asked

“Do I need exogenous ketones?”

No. For most goals (weight loss, glycemic control, mental clarity), food‑based ketosis suffices; supplements add cost, can cause GI upset, and don’t replace diet quality. Focus on whole‑food keto with UPF avoidance.

Quick‑start shopping list (whole‑food keto)

• Proteins: salmon, sardines, tuna, eggs, chicken thighs, ground beef, Greek yogurt (unsweetened).
• Veg/fruit: leafy greens, broccoli/cauli, zucchini, peppers, cucumbers, tomatoes, avocado, berries (small portions).
• Fats/flavor: extra‑virgin olive oil, avocado oil, olives, nuts/seeds, herbs, spices, lemon, vinegars, mustard.
• Pantry: chia, flax, psyllium, canned fish, low‑sodium broth.

Bottom line (action steps for this week)

1. Audit your pantry: circle anything with long additive lists—swap for whole‑food equivalents.
2. Set macros: 20–50 g net carbs, protein 1.2–1.6 g/kg, fats to appetite from minimally processed sources.
3. Batch‑cook two proteins and two veg each weekend; keep olives, nuts, eggs, and yogurt on hand.
4. Track your ketones and blood pressure; recheck ApoB‑focused lipids at 6–12 weeks and adjust fats if needed. ^[19]

References

• Wang C, Du M, et al. Ultraprocessed Food Consumption and Risk of Early‑Onset Colorectal Cancer Precursors Among Women. JAMA Oncology. Published online November 13, 2025. ^[20]
• Mass General Brigham press release summarizing the study, November 13, 2025. ^[21]
• News coverage on November 14–15, 2025, corroborating findings and context. ^[22]
• JAMA editorial coverage on UPFs as a public‑health challenge, 2025. ^[23]
• ACC summary linking UPFs to cardiometabolic outcomes (systematic review overview), 2025. ^[24]
• Martínez‑Montoro JI, et al. Calorie‑restricted KD vs MedDiet vs TRE vs mADF for obesity (RCT), BMC Medicine, July 1, 2025. ^[25]
• Zhang N, et al. Two‑week modified ketogenic diet: lipoprotein subclasses, GDF15, FGF21, Journal of Translational Medicine, November 7, 2025. ^[26]
• WHO Guideline on lower‑sodium salt substitutes, January 27, 2025. ^[27]
• University of Utah Health report on long‑term keto risks in mice (Science Advances), October 2025. ^[28]