Can a carnivore diet help patients with Inflammatory Bowel Disease (IBD) gain weight?

Carnivore Diet for Weight Gain in IBD: Not Recommended

A carnivore diet is not recommended for patients with IBD seeking to gain weight, as it represents a highly restrictive dietary approach that contradicts current evidence-based guidelines and poses significant risks of micronutrient deficiencies and muscle mass loss in this vulnerable population. 1

Why the Carnivore Diet Is Problematic for IBD Patients

Contradicts Evidence-Based Dietary Recommendations

• Current guidelines from ESPEN (2023) and AGA (2024) recommend a Mediterranean diet rich in fruits, vegetables, monounsaturated fats, complex carbohydrates, and lean proteins—the opposite of a carnivore diet's approach. 1
• The Mediterranean diet has demonstrated improved quality of life, lower rates of active disease, and reduced inflammatory biomarker elevation in IBD patients after 6 months of adherence. 1
• Guidelines explicitly warn against restrictive diets in IBD patients due to the high prevalence of micronutrient deficiencies and sarcopenia. 1

Risk of Worsening Nutritional Deficiencies

• IBD patients are already at increased risk for malnutrition, with deficits more common in Crohn's disease than ulcerative colitis, and a carnivore diet would eliminate entire food groups containing essential nutrients. 1
• Patients with IBD require regular monitoring for vitamin D, iron, folate, and vitamin B12 deficiencies (especially those with ileal disease or resection). 1
• The ESPEN guidelines specifically state that "the patient on a restrictive diet is at risk of further deficiencies and muscle mass loss, especially in catabolic states such as those associated with IBD flares." 1

Inadequate for Addressing Sarcopenia

• Low muscle mass affects 28% of Crohn's disease patients and 13% of ulcerative colitis patients, with sarcopenia reported in 12% of IBD patients. 1
• The reference treatment for sarcopenia requires adequate protein intake (1.2-1.5 g/kg/day during active disease) PLUS resistance training—not dietary restriction. 1
• While a carnivore diet provides protein, it eliminates the diverse nutrient profile needed to support muscle synthesis and overall health in IBD patients. 1

Evidence-Based Approach to Weight Gain in IBD

Appropriate Nutritional Strategy

• Increase protein intake to 1.2-1.5 g/kg/day during active disease (1.0 g/kg/day in remission) from diverse sources including lean meats, fish, eggs, legumes, and dairy if tolerated. 1
• Follow a Mediterranean dietary pattern with adequate calories from whole foods, not restrictive elimination diets. 1
• Energy requirements may be elevated in underweight IBD patients (those <90% ideal body weight show significantly higher energy expenditure per kg body weight). 2

Exercise as Essential Component

• All IBD patients should engage in endurance training (minimum 30 minutes, three times weekly), with resistance training specifically recommended for those with reduced muscle mass. 1
• Exercise interventions improve quality of life, are safe, and benefit IBD-specific physical and psychosocial symptoms. 1

When to Involve Specialists

• All patients with complicated IBD, malnutrition, or requiring complex nutrition therapies warrant co-management with a registered dietitian. 1
• Regular screening for malnutrition should assess unintended weight loss, edema, fluid retention, and fat/muscle mass loss. 1

Critical Pitfalls to Avoid

• Never recommend low-calorie or highly restrictive diets during active disease—this worsens outcomes. 1
• Avoid focusing solely on weight without addressing body composition (patients may have sarcopenic obesity). 1
• Do not assume weight gain from biologic therapy will solve nutritional deficits—weight gain occurs modestly (approximately 1.3 kg at 54 weeks) but doesn't address underlying malnutrition. 3
• Restrictive diets like carnivore eliminate fiber and plant-based nutrients that may have protective effects on the intestinal microbiome and epithelial function. 4