Oncology Nutrition

Citation model. Claims grounded in AllNutrition's trust-scored library carry an inline bracketed reference [n] linking to the References section, which lists each source's evidence level and AllNutrition trust score (0–1). Where an AllNutrition query returned an overall evidence_strength and consensus_level, those labels are surfaced in the Evidence Review so readers can calibrate confidence. Only sources actually returned by the tool are cited; no trust scores are invented.

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1. Introduction

Oncology nutrition sits at an unusual fault line in evidence-based medicine: the primary-prevention evidence is among the strongest in all of nutrition science, while the "anti-cancer diet" claims patients bring to clinic after a diagnosis are frequently weak, preliminary, or actively harmful. A physician who conflates these two evidence bases does real damage — either by under-selling genuinely modifiable cancer risk (obesity, alcohol, processed meat) or by allowing a newly diagnosed, already-vulnerable patient to pursue a restrictive "starve the tumor" diet that accelerates the single strongest predictor of poor cancer outcomes: involuntary weight loss.

This module draws a firm line between three distinct clinical contexts that are too often blurred in both the lay press and well-meaning clinical conversation: primary prevention (diet's role in whether cancer develops at all, where evidence from the World Cancer Research Fund/American Institute for Cancer Research [WCRF/AICR] Continuous Update Project is robust), active treatment (diet's role once a tumor is present and therapy is underway, where cachexia dominates the clinical picture and most "metabolic" diet claims remain unproven), and survivorship (diet's role in recurrence and long-term mortality after treatment, where a smaller but still meaningful evidence base exists). Understanding cancer cell metabolism — the Warburg effect — is essential background, but students must resist the common inferential leap from "cancer cells prefer glucose" to "starving patients of carbohydrate treats cancer." That leap is not supported by current human evidence and can be lethal in a population already at high risk of malnutrition.

2. Learning Objectives

By the end of this module, the learner will be able to:

1. Summarize the WCRF/AICR evidence base for diet, weight, alcohol, and cancer prevention, including the IARC classification of processed and red meat.
2. Explain the Warburg effect and cancer metabolic reprogramming, and articulate why this mechanism does not straightforwardly justify carbohydrate-restrictive "anti-cancer" diets in patients.
3. Describe the pathophysiology of cancer cachexia (inflammation, proteolysis, anorexia) and explain why simple caloric/protein supplementation routinely fails to reverse it.
4. Apply validated malnutrition screening tools in oncology and identify the ESPEN multimodal management framework for cachexia.
5. Critically evaluate popular but weakly evidenced claims — the ketogenic diet as cancer treatment, fasting around chemotherapy, "sugar feeds cancer," and antioxidant supplementation during treatment — against the strength of the underlying data.
6. Counsel patients accurately on soy and breast cancer, survivorship dietary patterns, and the distinct roles of enteral versus parenteral nutrition, including in advanced disease.

3. Scientific Foundations

3.1 Diet, obesity, and cancer prevention: the WCRF/AICR framework

The WCRF/AICR Continuous Update Project distills decades of pooled cohort and trial evidence into seven operational recommendations for cancer prevention: maintain a healthy weight, be physically active, eat a diet rich in whole grains, vegetables, fruit, and legumes (targeting roughly 400 g/day of fruit and vegetables and >25 g/day of fiber), limit fast/processed foods, limit red and processed meat, limit sugar-sweetened beverages, and limit or avoid alcohol [1]. Among these, excess body weight is the single largest modifiable driver of cancer risk after tobacco: a 5 kg/m² increase in BMI is associated with an 11% increase in obesity-related cancer risk, and roughly 40% of cancer cases and 50% of cancer deaths in the U.S. are attributable to modifiable risk factors, with obesity a leading contributor [1]. The mechanistic basis is chronic metabolic stress — hyperinsulinemia activating PI3K/Akt/mTOR growth signaling, adipose-derived estrogen production (particularly relevant to postmenopausal breast and endometrial cancer), and pro-inflammatory cytokines (CRP, IL-6, TNF-α) [1][2]. Weight loss reverses risk in a graded fashion: even 5% body-weight loss is associated with a 12% reduction in postmenopausal breast cancer risk, and bariatric surgery reduces breast cancer risk by up to 64% for ER-negative disease [1]. Notably, metabolic dysfunction — not BMI alone — independently predicts risk: metabolically unhealthy individuals of normal weight still show 37–84% elevated cancer risk versus metabolically healthy peers [3].

3.2 Alcohol, meat, and fiber: the strongest single-exposure evidence in oncology

Alcohol is classified by IARC as a Group 1 carcinogen, and there is no established safe threshold — even low intake (>10 g/day) is associated with elevated postmenopausal breast cancer risk, and >12 g/day (roughly one standard drink) raises colorectal cancer risk by ~8% [4][5][6]. The mechanism runs through acetaldehyde, ethanol's genotoxic first metabolite, which forms DNA adducts and interferes with folate-dependent one-carbon metabolism and estrogen metabolism [5]. This is one area where the Mediterranean diet's traditional inclusion of moderate wine consumption is now explicitly at odds with cancer-prevention guidance; global health bodies increasingly recommend abstinence for cancer prevention specifically, even while acknowledging plausible cardiovascular trade-offs [7][8].

Processed meat is IARC Group 1 (carcinogenic to humans) and red meat is Group 2A (probably carcinogenic) [9][10]. Pooled cohort data show roughly 18–19% higher colorectal cancer risk per 50 g/day of processed meat and ~17% higher risk per 100 g/day of red meat, with beef showing the strongest single-meat association (~30% increase) [9][11][12]. Mechanisms include heme iron catalyzing N-nitroso compound formation, nitrite/nitrate conversion to carcinogenic nitrosamines in processed meat, and heterocyclic amines and polycyclic aromatic hydrocarbons generated by high-heat cooking [9][10].

Dietary fiber shows a consistent, dose-responsive protective association: each 5 g/day increment in fiber intake is linked to an 18% reduction in colorectal-cancer-specific mortality, and whole grains specifically (not isolated fiber supplements) confer a 16% risk reduction [13][14][15]. The mechanism runs through microbial fermentation to short-chain fatty acids, particularly butyrate, which serves as the primary energy source for healthy colonocytes while inducing apoptosis and inhibiting proliferation in colorectal cancer cells, alongside dilution of luminal carcinogens and reduced transit time [13][16].

3.3 Cancer cell metabolism: the Warburg effect

Otto Warburg's century-old observation remains mechanistically central: most cancer cells preferentially ferment glucose to lactate (aerobic glycolysis) even when oxygen is abundant, rather than relying on the far more energy-efficient mitochondrial oxidative phosphorylation used by normal cells [17][18]. Aerobic glycolysis yields only ~2 ATP per glucose versus ~36 via oxidative phosphorylation, but it is faster and — critically — diverts glycolytic intermediates into the pentose phosphate pathway and other branches to generate the nucleotides, amino acids, and lipids needed for rapid proliferation [17][19]. This reprogramming is driven by oncogenic signaling (MYC, KRAS, PI3K/Akt/mTOR) acting on enzymes like hexokinase-2, PKM2, and LDHA, and it has real clinical downstream effects: lactate export acidifies the tumor microenvironment, promoting invasion, angiogenesis, and immune evasion, and tumors can directly compete with T cells for glucose, contributing to immune exhaustion [17][20][21]. Importantly, cancer cells retain substantial metabolic plasticity — many can and do shift toward oxidative phosphorylation depending on nutrient availability and therapeutic pressure, and a "reverse Warburg effect" exists in which stromal cells perform glycolysis and feed lactate to tumor cells [19]. This plasticity is the central reason the intuitive leap from "tumors like glucose" to "starve the tumor with carbohydrate restriction" fails clinically — described further in §5.

3.4 Cancer cachexia pathophysiology

Cachexia is a distinct clinical entity from simple starvation, and understanding this distinction is the single most important concept in oncology nutrition for a treating physician. It is a self-reinforcing, tumor-driven syndrome of whole-body catabolism arising from three intersecting processes: systemic inflammation, muscle proteolysis, and anorexia [22]. Tumors and host immune cells release pro-inflammatory cytokines (IL-6, TNF-α, IL-1β) that drive a hepatic acute-phase response and, independently, are associated with a measurable energy deficit — roughly 250 kcal and 17 g protein per day in patients with elevated CRP [23][24]. Cytokine signaling activates FOXO transcription factors, which upregulate the muscle-specific ubiquitin ligases MuRF1 and Atrogin-1, driving ubiquitin-proteasome-mediated breakdown of myofibrillar protein, while simultaneously suppressing the PI3K/Akt/mTOR pathway needed for muscle protein synthesis — a state of anabolic resistance in which muscle cannot efficiently use the amino acids it is given [22][24]. Anorexia is centrally mediated: cytokines and stress factors such as GDF-15 suppress ghrelin signaling and appetite centers, compounding intake-driven weight loss with symptom burden (nausea, mucositis, early satiety) [22][25]. The result is a catabolic feedback loop in which metabolites released from wasting muscle and fat fuel both tumor bioenergetics and further hepatic gluconeogenesis — which is precisely why cachexia cannot be reliably reversed by feeding alone [22][26].

4. Clinical Relevance

Malnutrition affects an estimated 20–70% of cancer patients and contributes to 10–20% of cancer deaths, independent of the tumor itself [27][28]. Muscle wasting (sarcopenia) predicts survival, treatment toxicity, and postoperative complications regardless of BMI, meaning a patient can appear well-nourished by weight or BMI alone while being profoundly sarcopenic and at elevated risk [28][29]. Every oncology clinician will be asked, repeatedly, about "anti-cancer diets," ketogenic protocols, fasting before chemotherapy, and whether to take antioxidant supplements — and every oncology clinician will care for patients whose appetite has collapsed under the weight of inflammation and symptom burden. The clinical skill this module builds is triage: recognizing when a dietary question is about prevention (where the guidance is strong and directive), active treatment (where cachexia management and symptom control dominate, and most "metabolic" claims remain unproven or risky), or survivorship (where a smaller, real evidence base supports specific pattern-level recommendations).

5. Evidence Review

Established (high confidence):

• Excess body weight, alcohol, and red/processed meat are causal or probable-causal contributors to cancer incidence; dietary fiber and whole-grain intake are protective for colorectal cancer. AllNutrition evidence_strength: strong, consensus_level: moderate [1][4][9][13].
• The Warburg effect (aerobic glycolysis) is a well-established feature of cancer cell metabolism with clear mechanistic and biomarker support (e.g., FDG-PET imaging). evidence_strength: limited (for the broader clinical-translation questions built on it) *, consensus: moderate [17][18].
• Antioxidant supplementation during active chemotherapy/radiotherapy is not routinely recommended and may reduce treatment efficacy or increase recurrence in some settings (breast cancer polyvitamin/antioxidant use, β-carotene in smokers, vitamin E and prostate cancer); targeted correction of documented deficiencies is distinct from routine antioxidant supplementation. evidence_strength: moderate, consensus: moderate [30][31][32].

Probable:

• Malnutrition screening (NRS-2002, MUST, PG-SGA, GLIM criteria) meaningfully predicts length of stay, treatment toxicity, and survival, though no single tool has ideal content validity against all consensus definitions of malnutrition. evidence_strength: strong, consensus: moderate [27][33][34].
• ESPEN's multimodal cachexia framework (nutritional screening plus anti-inflammatory support, protein/leucine-enriched supplementation, physical activity, and escalation through oral→enteral→parenteral routes only as needed) is the standard of care, though evidence that any single component reverses established cachexia is limited. evidence_strength: strong, consensus: moderate [24][35].
• Moderate whole-food soy intake (2–3 servings/day) is safe and possibly protective for breast cancer survivors; high-dose isoflavone supplements (≥100 mg) should be avoided. evidence_strength: strong, consensus: moderate [36][37].
• Mediterranean and healthful plant-based dietary patterns are associated with modestly reduced overall cancer incidence and mortality, and with improved survival post-diagnosis. evidence_strength: strong, consensus: moderate [38][39][40][41].

Emerging:

• Omega-3/EPA supplementation (≈2 g/day) in cancer cachexia shows modest, inconsistent benefit on weight and lean mass across tumor types — meaningful in gastric and breast cancer trials, but not significant for lean body mass in a pancreatic-cancer meta-analysis. evidence_strength: strong (for the body of trials as a whole, with low-certainty individual findings), consensus: moderate [42][43][44].
• Fasting and fasting-mimicking diets around chemotherapy show favorable preclinical signals (protecting normal cells while sensitizing tumor cells) and early-phase human feasibility/safety data, but efficacy and long-term safety in humans remain unestablished; adherence and malnutrition risk are real concerns. evidence_strength: limited, consensus: mixed [45][46][47].
• Direct evidence for artificial nutrition support (enteral or parenteral) altering survival in advanced/terminal cancer specifically is limited within the queried literature; broader critical-care and intestinal-failure literature establishes that parenteral nutrition carries meaningful complication burden (catheter infection, metabolic derangement) and should be reserved for patients who cannot be fed enterally. evidence_strength: limited — noted evidence gap; extrapolated cautiously from adjacent literature [48][49].

Controversial:

• The ketogenic diet as adjunctive cancer therapy: mechanistically plausible (glucose restriction should disadvantage glycolysis-dependent tumor cells) and safe/feasible in glioblastoma, but clinical trials elsewhere show poor tolerability (30% dropout, worse in head/neck and lung cancer trials) and, in one RCT of recurrent glioma, no progression-free-survival benefit over standard diet. evidence_strength: strong (for the safety/preliminary literature), but the efficacy claim is unsupported by rigorous trials, consensus: moderate [50][51][52].
• "Sugar feeds cancer": partially grounded (glucose fuels the Warburg effect; hyperglycemia and insulin/IGF-1 signaling promote proliferation and metastasis in preclinical and some clinical data) but frequently over-extended into the false conclusion that ordinary dietary sugar intake directly "feeds" an existing tumor in a clinically actionable way, or that eliminating sugar starves it. evidence_strength: limited, consensus: moderate [53][54][20].

Unsupported / overstated:

• That carbohydrate restriction or fasting can substitute for or meaningfully outperform standard oncologic therapy — no queried evidence supports this, and several trials show harm from poor tolerability and unintended weight loss [51][52].
• That antioxidant megadosing during active treatment is protective — the directionally opposite finding (potential harm/interference with treatment) is better supported [30][31].

6. Practical Clinical Applications

Prevention (asymptomatic, pre-diagnosis patients). This is the setting for directive counseling: weight management toward a healthy BMI, ≥150–300 min/week moderate activity, a fiber-rich plant-forward diet (≥25 g/day fiber, ~400 g/day fruit/vegetables), limiting red meat to <3 portions/week and avoiding processed meat, minimizing sugar-sweetened beverages, and either avoiding alcohol or keeping it to the lowest feasible level [1][9][13]. This advice can be given with confidence proportional to the strength of the underlying evidence.

Active treatment (patient currently receiving chemotherapy, radiotherapy, or surgery). The priority inverts: the clinical goal is preventing and treating cachexia and malnutrition, not pursuing restrictive "anti-cancer" diets. Screen early and repeatedly with a validated tool regardless of BMI, since sarcopenia can be masked by normal or elevated weight [27][33]. Favor small frequent high-calorie, high-protein meals; use oral nutritional supplements before escalating to enteral nutrition, and reserve parenteral nutrition for a non-functional or inaccessible GI tract [24][48]. Manage nausea, mucositis, and dysgeusia proactively — elemental supplements started before chemotherapy reduce mucositis severity, and omega-3/arginine/glutamine-enriched formulas may reduce treatment-related toxicity [55][56]. Do not recommend ketogenic diets, prolonged fasting, or high-dose antioxidant supplementation as routine adjuncts outside a clinical trial; if a motivated patient wishes to pursue one, involve an oncology dietitian, monitor weight and muscle mass closely, and treat unintended weight loss as a stop signal [50][30].

Survivorship (post-treatment, disease-free or stable). This is where dietary pattern-level recommendations regain solid footing: return to WCRF-style healthy-weight, plant-forward, low-alcohol guidance; for breast cancer survivors specifically, moderate whole-food soy is safe and possibly protective, structured exercise confers a 20–40% reduction in recurrence risk in some analyses, and Mediterranean-pattern adherence is associated with improved survival across several tumor types [36][38][41][57].

When not to intervene aggressively. In advanced, actively dying patients, aggressive nutrition support (particularly parenteral nutrition) has not been shown to extend meaningful survival and carries real complication burden (catheter sepsis, metabolic derangement); decisions should be individualized, patient/family-centered, and revisited as goals of care evolve — a domain where the nutrition evidence itself is thin and ethical, values-based discussion carries the greater weight [48][49].

7. Clinical Pearls

• A patient can look "fine" on the scale and still be sarcopenic and cachectic — weight and BMI alone will miss this; ask about grip strength, functional decline, and screen with a validated tool.
• Cachexia is not starvation and will not respond to calories and protein alone; it requires a multimodal approach addressing inflammation, not just intake.
• "Cancer cells prefer glucose" is true and mechanistically interesting; it is not, by itself, a license to recommend carbohydrate restriction to an already-catabolic patient.
• The evidence for diet in preventing cancer is much stronger than the evidence for diet treating cancer once present — say so explicitly to patients.
• Antioxidant supplements during active chemo/radiotherapy are a "when in doubt, don't" area outside of correcting a documented deficiency.
• Soy is safe, and likely modestly protective, for breast cancer survivors at whole-food doses — this is one of the more reassuring, evidence-backed answers you can give a worried patient.

8. Common Misconceptions

• "Sugar feeds cancer, so cutting out all carbohydrates will slow tumor growth." Cancer cells do preferentially use glucose, but tumors retain metabolic plasticity, and no rigorous human trial shows that dietary carbohydrate restriction alone changes cancer outcomes; meanwhile the unintended weight loss risk in an already-vulnerable population is real [19][53].
• "The ketogenic diet is a proven cancer treatment." It is mechanistically plausible and has reasonable safety data in glioblastoma specifically, but trial evidence across cancer types is mixed to negative, and adherence/tolerability is often poor [50][51].
• "More antioxidants during chemo can only help." Some evidence suggests the opposite — antioxidants may blunt the oxidative mechanisms by which chemotherapy and radiotherapy kill cancer cells [30][31].
• "Soy is dangerous for breast cancer patients because it's estrogenic." Whole-food soy at typical dietary doses is not associated with increased recurrence and may be modestly protective; the caution applies specifically to high-dose isoflavone supplements, not tofu or soymilk [36][37].
• "If a patient isn't eating, more IV nutrition is always better." Aggressive parenteral feeding is not synonymous with better care, particularly in advanced disease, and carries infection and metabolic risk; the decision should be individualized [48][49].

9. Summary

Oncology nutrition requires clinicians to hold two different evidence standards simultaneously. The prevention evidence — obesity as a major modifiable cancer driver, alcohol as a no-safe-threshold Group 1 carcinogen, processed and red meat as IARC-classified colorectal carcinogens, and fiber/whole grains as protective — is robust, dose-responsive, and should be communicated with confidence. The treatment-phase evidence is far weaker and the clinical stakes of getting it wrong are high: cancer cachexia is a distinct, inflammation-driven catabolic syndrome that resists simple feeding, and popular "anti-cancer diet" strategies — ketogenic eating, fasting around chemotherapy, sugar elimination, antioxidant megadosing — range from mechanistically plausible-but-unproven to actively risky in a population where unintended weight loss is the single strongest negative prognostic sign. Survivorship recommendations occupy a middle ground, supported by a real if smaller evidence base for weight management, plant-forward dietary patterns, moderate soy intake, and physical activity. The physician's task is to validate patients' desire for agency over their diagnosis while steering that desire toward the interventions the evidence actually supports — and to recognize, screen for, and treat cachexia before it becomes irreversible.

10. References

Ordered by evidence strength / relevance. Evidence level and AllNutrition trust score (0–1) as returned by the tool.

1. Global trends in obesity-related cancer: risk factors, prevention, and policy interventions. Food and Agricultural Immunology (2026). Review — trust 0.677.
2. Obesity, inflammation, and the Mediterranean diet in cancer. Food and Agricultural Immunology (2026). Review — trust 0.677.
3. Metabolic Health Matters More Than Weight In Cancer Prevention. Journal of Obesity & Metabolic Syndrome (2026). Review — trust 0.695.
4. Rethinking ethanol consumption and colorectal carcinogenesis: an insight from diet and gut microbiota. Frontiers in Cellular and Infection Microbiology (2026). Review — trust 0.775.
5. The role of nutrition in cancer prevention: the effect of dietary patterns, bioactive compounds, and metabolic pathways on cancer development. Food and Agricultural Immunology (2025). Review — trust 0.717.
6. Alcohol consumption trajectories and risk of breast cancer among postmenopausal women: a Danish cohort study. European Journal of Epidemiology (2024). Observational — trust 0.742.
7. Updates on Mediterranean diet and health status: active ingredients and pharmacological mechanisms. British Journal of Pharmacology (2026). Review — trust 0.792.
8. Changes in alcohol consumption and the risk of postmenopausal breast cancer in the European Prospective Investigation into Cancer and Nutrition cohort. European Journal of Nutrition (2026). Observational — trust 0.762.
9. Dietary Factors Modulating Colorectal Carcinogenesis. Nutrients (2021). Review — trust 0.838.
10. The meat processing exposome in Africa: integrating traditional culinary practices, environmental co-exposures, and cancer prevention strategies. Frontiers in Oncology (2026). Review — trust 0.748.
11. Systematic Analysis of the Differential Effects of Red Meat on Colorectal Cancer Risks: A Meta-Analytic Approach. Journal of Gastrointestinal Cancer (2025). Review — trust 0.742.
12. Association of meat consumption with the risk of gastrointestinal cancers: a systematic review and meta-analysis. BMC Cancer (2023). Systematic review — trust 0.792.
13. Global, regional and national burden of colorectal cancer attributable to low-fiber diet from 1990 to 2021: a systematic analysis of the global burden of disease study 2021. Frontiers in Nutrition (2026). Systematic review — trust 0.838.
14. The association between dietary fiber intake and risk of lung cancer: a GRADE-assessed systematic review and dose response meta-analysis of prospective cohort studies. Nutrition Journal (2026). Systematic review — trust 0.842.
15. Dietary Manipulation on Gut Microbiome in Patients with Diabetes and Colorectal cancer. Current Nutrition Reports (2025). Review — trust 0.742.
16. Gut microbiota: A key player for soluble dietary fiber in regulating inflammatory disease. Journal of Advanced Research (2025). Review — trust 0.73.
17. Glycolytic reprogramming in cancer: immune crosstalk, nutrient competition, and supportive care perspectives. Frontiers in Immunology (2026). Review — trust 0.938.
18. Cancer metabolism: from the Warburg effect to precision therapy. Frontiers in Immunology (2026). Review — trust 0.675.
19. Energy metabolism, nutrition and cancer. Seminars in Cancer Biology (2026). Review — trust 0.748.
20. Targeting the cancer metabolism—immunity interface: update and perspectives. Experimental Hematology & Oncology (2026). Review — trust 0.7.
21. Metabolic rewiring of the tumor microenvironment: therapeutic intervention of multi-pathway adaptations to impede cancer metastasis. Frontiers in Molecular Biosciences (2026). Review — trust 0.8.
22. Cancer cachexia: A tumor-driven disorder of whole-body homeostasis. Cancer Cell (2026). Review — trust 0.776.
23. Linking Inflammation to Reduced Food Intake in Advanced Cancer: A Prospective Observational Study. Current Oncology (2026). Observational — trust 0.752.
24. ESPEN expert group recommendations for action against cancer-related malnutrition. Clinical Nutrition (2017). Review — trust 0.688.
25. Feeding Behaviour in the KPC Model of Pancreatic Cancer-Associated Cachexia. Journal of Cachexia, Sarcopenia and Muscle (2026). Observational — trust 0.77.
26. Inhibition Of Ceramide Synthesis Ameliorates Body Wasting In A Cancer Cachexia Model. The Journal of Clinical Investigation (2026). Observational — trust 0.813.
27. Effects of Dietary Interventions on Nutritional Status in Patients with Gastrointestinal Cancers: A Systematic Review. Biomedicines (2026). Systematic review — trust 0.807.
28. Impact of malnutrition and nutritional support after gastrectomy in patients with gastric cancer. Annals of Gastroenterological Surgery (2024). Review — trust 0.85.
29. Preoperative Nutrition in Cancer Patients. Surgical Clinics of North America (2026). Review — trust 0.777.
30. Vitamin B3 derivatives support pancreatic cancer cell survival and chemotherapy resistance. Cancer Letters (2026). Observational — trust 0.688.
31. Vitamins and Cancer Risk: A Comprehensive Review of Epidemiologic and Clinical Evidence. Kansas Journal of Medicine (2026). Review — trust 0.662.
32. Impact of Dietary Supplements on Clinical Outcomes and Quality of Life in Patients with Breast Cancer: A Systematic Review. Nutrients (2025). Systematic review — trust 0.782.
33. NRS2002 outperforms GNRI and PG-SGA SF in GLIM-based malnutrition identification among elderly patients with gastrointestinal malignancy. Nutrition (2026). Observational — trust 0.785.
34. Content validity across methods of malnutrition assessment in patients with cancer is limited. Journal of Clinical Epidemiology (2016). Systematic review — trust 0.67.
35. What nutritional interventions can effectively treat sarcopenia in older adults with cancer? A systematic review. Journal of Geriatric Oncology (2026). Systematic review — trust 0.842.
36. Integrative Medicine for Breast Cancer Survivors. Seminars in Radiation Oncology (2026). Review — trust 0.787.
37. Lifetime Soy Intake and Adult Mammographic Density in Chinese Premenopausal Women. Nutrients (2026). Observational — trust 0.743.
38. Efficacy of Mediterranean diet for the primary prevention of oncological diseases: A systematic review and meta-analysis. Nutrition (2026). Systematic review — trust 0.86.
39. Association between EAT-Lancet diet adherence and cancer incidence/mortality: a systematic review and meta-analysis. Frontiers in Oncology (2026). Systematic review — trust 0.838.
40. Healthful and unhealthful plant-based diets and site-specific cancer risk: a systematic review and meta-analysis of observational studies. European Journal of Nutrition (2026). Systematic review — trust 0.842.
41. Mediterranean diet in cancer patients' survival: A systematic review and meta-analysis for tertiary prevention. Nutrition (2026). Systematic review — trust 0.857.
42. Effect of polyunsaturated fatty acids supplementation on nutritional status in patients with pancreatic cancer: a systematic review and meta-analysis. PeerJ (2026). Systematic review — trust 0.827.
43. Effectiveness of nutritional intervention in improving the nutritional status of patients with gastric cancer after gastrectomy. Clinical Nutrition Open Science (2026). RCT — trust 0.832.
44. The Effects of Omega-3 Fatty Acids and Vitamin D Supplementation on the Nutritional Status of Women with Breast Cancer in Palestine: An Open-Label Randomized Controlled Trial. Nutrients (2024). RCT — trust 0.792.
45. Roles of Caloric Restriction, Ketogenic Diet and Intermittent Fasting during Initiation, Progression and Metastasis of Cancer in Animal Models: A Systematic Review and Meta-Analysis. PLOS ONE (2014). Systematic review — trust 0.912.
46. Targeting Glucose Metabolism to Enhance Immunotherapy: Emerging Evidence on Intermittent Fasting and Calorie Restriction Mimetics. Frontiers in Immunology (2019). Review — trust 0.867.
47. Fasting and Fasting-Mimicking Diets as Adjunctive Strategies in Cancer Therapy: Mechanisms, Evidence, and Clinical Implications. International Journal of General Medicine (2026). Review — trust 0.68.
48. ESPEN guideline on clinical nutrition in the intensive care unit. Clinical Nutrition (2018). Guideline — trust 0.828. (Adjacent critical-care literature; oncology-specific end-of-life nutrition trial evidence was not returned and is noted as a gap — see §5.)
49. Metabolic complications of home parenteral nutrition and chronic intestinal failure and indications for intestinal transplantation. Clinical Nutrition ESPEN (2026). Review — trust 0.725.
50. Efficacy and safety of ketogenic diet in glioblastoma: an updated systematic review and meta-analysis. Neurological Sciences (2026). Systematic review — trust 0.807.
51. Mitochondria-targeted strategies in cancer radiotherapy: from ROS regulation to immunogenic cell death. Frontiers in Cell and Developmental Biology (2026). Review — trust 0.675.
52. The advent of precision nutrigeroscience in cancer: from clinic towards molecular biology. Journal of Advanced Research (2025). Review — trust 0.625.
53. Emerging insights into the impact of systemic metabolic changes on tumor-immune interactions. Cell Reports (2025). Review — trust 0.74.
54. The interplay of dietary sugar, chronic inflammation, and bladder cancer: mechanistic insights, evidence, and prevention strategies. Frontiers in Immunology (2026). Review — trust 0.715.
55. Summary of best evidence for nutritional and dietary interventions in managing chemotherapy-induced gastrointestinal toxicity in cancer patients. Nutrition (2026). Systematic review — trust 0.86.
56. Nutritional management and oral health-related outcomes in head and neck cancer treated with radiotherapy or chemoradiotherapy: a systematic review. BMC Oral Health (2026). Systematic review — trust 0.825.
57. Optimizing Breast Cancer Survivorship: Addressing Lifestyle, Weight Management, and Psychological Health. American Society of Clinical Oncology Educational Book (2026). Review — trust 0.765.

Supporting sources also surfaced: Metabolic Syndrome Components and Cancer Risk in Normal-Weight Subjects (J Clin Med 2026, systematic review, trust 0.857); The effect of a person-centred lifestyle programme on cancer-related fatigue in colorectal cancer survivors (BJN 2025, RCT, trust 0.82); Diet Quality by Race and Ethnicity in Adult Cancer Survivors, NHANES 2011–2020 (J Acad Nutr Diet 2026, observational, trust 0.77); Nutritional status and cancer survival among rural Chinese women (Front Public Health 2026, review, trust 0.65); Health Benefits of Vegetarian Diets (Foods 2024, review, trust 0.67); A comprehensive evaluation of epidemiological evidence on processed meat intake — umbrella review (Front Public Health 2026, systematic review, trust 0.78); Application and Modification of Nutritional Assessment Tools in Hematologic Malignancies (Cancers 2026, observational, trust 0.717).