Why do people with Crohn's disease gain weight in South Africa?

Weight gain in Crohn's disease is almost always driven by corticosteroid treatment — particularly prednisolone, which causes fluid retention, increased appetite, fat redistribution to the abdomen and face, and muscle wasting. During flares, reduced physical activity also contributes. Paradoxically, during remission, improved absorption and appetite can lead to weight gain if dietary habits do not adjust. The steroid-related weight gain typically reverses once prednisolone is tapered, though this takes weeks to months.

What is the best diet for Crohn's disease in South Africa?

There is no single universal Crohn's diet — the right diet differs between active flares and remission. During flares: low-fibre, low-residue foods that minimise bowel stimulation — white rice, boiled chicken, boiled eggs, plain yoghurt, well-cooked vegetables without skins. During remission: a Mediterranean-style anti-inflammatory diet is best supported by evidence — oily fish, olive oil, vegetables, fruit, legumes (if tolerated), and lean protein. The Specific Carbohydrate Diet (SCD) has some evidence but should be supervised. A registered dietitian with IBD experience is essential — find one through ADSA (adsa.org.za).

Can I lose weight safely with ulcerative colitis?

Yes — with the right approach. During remission, a moderate calorie deficit (500–1,000 kJ/day below maintenance) with a Mediterranean-style diet is safe and appropriate. Avoid extreme calorie restriction or high-fibre fad diets, which can irritate the colon. During active flares, weight loss via dietary restriction is dangerous — priority shifts to nutritional support and disease control. Always work with your gastroenterologist and a dietitian. In South Africa, UC is classified as a PMB condition under Prescribed Minimum Benefits, meaning medical aids must cover hospitalisation and gastroenterologist consultations.

How does prednisolone cause weight gain in IBD?

Prednisolone and other corticosteroids cause weight gain through several mechanisms: increased appetite and food cravings (particularly for carbohydrates and salt), fluid retention, redistribution of body fat to the abdomen, face (moon face), and back of the neck (buffalo hump), increased blood glucose (steroid-induced hyperglycaemia), and reduced muscle protein synthesis leading to muscle wasting. The weight gain is dose- and duration-dependent. Most patients see reversal within 3–6 months of tapering off steroids, though some fat redistribution can persist longer.

What are the best IBD resources in South Africa?

GESA (Gastroenterology Society of South Africa) at gesa.org.za is the primary professional body and maintains a specialist directory. Crohn's and Colitis South Africa (CCSA) at crohnsandcolitis.co.za is a patient support organisation. IBD is covered as a PMB (Prescribed Minimum Benefits) condition under chronic disease management in South Africa — consult your medical aid. Academic hospitals with IBD units include Groote Schuur (UCT), Chris Hani Baragwanath, Charlotte Maxeke (Wits), and Tygerberg.

Weight Loss With Inflammatory Bowel Disease in South Africa: Crohn's and UC Nutrition Guide

Anti-inflammatory foods for IBD weight management in South Africa

Inflammatory bowel disease (IBD) — encompassing Crohn's disease and ulcerative colitis (UC) — creates a uniquely challenging relationship with food and body weight. On one hand, active disease causes malabsorption, diarrhoea, and nutritional deficiencies that can lead to underweight and malnutrition. On the other, the corticosteroids used to control flares trigger significant weight gain, fluid retention, and metabolic disruption. Managing weight with IBD in South Africa means understanding which problem you are facing at any given time — and approaching it appropriately.

South Africa has an estimated 15,000–30,000 people living with IBD, with incidence rising among urban South Africans as Western dietary patterns become more prevalent. The condition is managed by gastroenterologists, and in the public sector it qualifies as a Prescribed Minimum Benefit (PMB) condition — meaning medical aids must cover specialist consultations and hospitalisation.

Crohn's vs Ulcerative Colitis: Weight Differences

Both conditions cause intestinal inflammation, but they differ in location and pattern — which affects weight differently:

Crohn's Disease

Can affect any part of the gastrointestinal tract from mouth to anus, but most commonly the small intestine (terminal ileum). Because the small intestine is the primary site of nutrient absorption, Crohn's disease carries a higher risk of malabsorption, nutritional deficiencies, and underweight during active disease. Complications such as strictures, fistulas, and intestinal resections compound this. Many Crohn's patients lose significant weight during flares and struggle to maintain healthy weight.

Ulcerative Colitis

Affects only the colon (large intestine), which is primarily involved in water absorption rather than nutrient absorption. UC patients are therefore less prone to malabsorption but still experience significant weight loss during severe flares due to bloody diarrhoea, reduced appetite, and systemic inflammation. During remission, UC patients often gain weight — sometimes excessively — particularly when on corticosteroids and with improved appetite.

The Steroid Problem: Prednisolone and Weight Gain in IBD

Corticosteroids — particularly prednisolone — remain a cornerstone of IBD flare management in South Africa, largely because they are inexpensive and rapidly effective. Prednisolone at doses of 40–60 mg/day (commonly used for moderate-to-severe flares) causes substantial metabolic disruption:

Increased appetite and cravings: Steroids activate appetite-stimulating pathways in the hypothalamus, producing intense hunger for carbohydrates and salty foods. Patients often describe a feeling of ravenous hunger that is physiologically driven, not a lack of willpower.
Fluid retention: Corticosteroids cause sodium and water retention via mineralocorticoid effects. Patients may retain 2–5 kg of fluid within the first week of high-dose prednisolone.
Fat redistribution: Long-term steroid use causes central fat accumulation (abdomen), moon face (fat in the cheeks), and a buffalo hump (fat at the back of the neck) — even while peripheral muscle is wasting.
Steroid-induced hyperglycaemia: High-dose steroids raise blood glucose, sometimes requiring temporary insulin treatment. This promotes further fat storage.
Muscle wasting: Despite weight gain from fat and fluid, steroids cause protein catabolism — muscle is broken down. This is a dangerous combination: more fat, less muscle, worsening metabolic health.

Strategies to minimise steroid weight gain:

Reduce sodium intake (limit processed foods, salty snacks, boerewors, bacon) to counter fluid retention
Increase protein intake to partially offset muscle catabolism — aim for 1.2–1.5 g protein per kg body weight daily
Limit refined carbohydrates to manage steroid-induced blood glucose spikes
Gentle resistance exercise where possible — even light bodyweight exercises preserve some muscle mass
Advocate with your gastroenterologist for the shortest effective steroid course and early transition to steroid-sparing biologics

Nutrition During an IBD Flare

During an active flare, weight management goals shift completely. The priority is nutritional support, disease control, and preventing malnutrition — not losing weight. Attempting to restrict calories during a flare is dangerous and counterproductive.

Low-Fibre, Low-Residue Approach

During active Crohn's or UC flares, a low-fibre, low-residue diet reduces bowel stimulation and helps manage symptoms:

White rice, white bread, plain pasta — the one time white carbohydrates are preferable to brown
Well-cooked, peeled vegetables (carrots, courgettes, butternut squash — widely available in SA)
Lean protein: boiled chicken, eggs, white fish, canned tuna in water
Low-fat dairy (if lactose-tolerant): plain yoghurt is gentle on the gut and provides protein and probiotics
Bananas — soft, low-fibre, easy to digest, potassium-rich (important for replacing electrolytes lost via diarrhoea)
Oral rehydration solution (ORS) or diluted coconut water to replace electrolytes

Foods to Avoid During Flares

Raw vegetables and salads
High-fibre foods: bran, wholewheat, legumes, dried fruit, nuts
Biltong and dried meats — high fibre equivalents; tough to digest
Spicy foods (peri-peri, chakalaka, hot sauces)
Alcohol — particularly beer, which is highly fermentable and irritates the gut lining
Carbonated drinks
Dairy during active flares if lactase is temporarily reduced

Exclusive Enteral Nutrition (EEN) for Crohn's

For moderate-to-severe Crohn's flares — particularly in children but increasingly in adults — exclusive enteral nutrition (EEN) via liquid formula feeds can induce remission with effectiveness comparable to corticosteroids, without the steroid side effects including weight gain. In South Africa, EEN is available at academic hospital IBD units and through some private gastroenterologists. Elemental formulas (Elemental 028, Peptamen) are used for those with severe malabsorption. Discuss this option with your gastroenterologist if you are concerned about repeat steroid courses.

Nutrition During IBD Remission: Losing Steroid Weight

Once you achieve remission and have tapered off corticosteroids, it is safe and appropriate to address any steroid-related weight gain. The steroid-driven fluid usually comes off within 2–4 weeks of stopping prednisolone without any dietary change. True fat gain takes longer to address.

Mediterranean-Style Diet in Remission

The Mediterranean diet has the strongest evidence base for maintaining IBD remission and supporting healthy weight. Applied to South African eating patterns:

Oily fish twice weekly: Sardines, pilchards (very affordable in SA at R15–R25/tin), salmon. Omega-3 fatty acids have direct anti-inflammatory effects on the gut.
Olive oil: Use for cooking and dressings. Oleocanthal in olive oil inhibits the same inflammatory pathway as ibuprofen.
Vegetables: Build up fibre tolerance gradually in remission — start with cooked vegetables before raw. Butternut, carrots, green beans, courgettes are well-tolerated starting points in SA.
Legumes: Re-introduce carefully. Brown lentils, canned chickpeas, and sugar beans are affordable SA staples. Start with small portions. Many IBD patients in remission tolerate legumes well.
Lean protein: Chicken, eggs, fish, low-fat biltong (plain beef, not highly spiced varieties). Limit red and processed meats — strong association with IBD flare risk.
Rooibos tea: South Africa's own anti-inflammatory drink. Aspalathin and quercetin in rooibos have documented anti-inflammatory effects relevant to IBD.

Calorie Approach in Remission

A modest deficit of 500–1,000 kJ/day is appropriate for gradual weight loss (0.25–0.5 kg/week) during remission. Aggressive calorie restriction is not advisable — IBD patients have elevated nutritional needs due to increased gut cell turnover and inflammation even in remission, and malnutrition risk is real.

Biologics and Weight

Biologics (infliximab/Remicade, adalimumab/Humira, vedolizumab/Entyvio) have transformed IBD management. They do not directly cause weight gain in the way steroids do. However, by inducing sustained remission and significantly improving quality of life, they often restore normal appetite and physical activity — which can lead to gradual weight gain if dietary habits are not adjusted. This is a far preferable situation to ongoing disease activity and undernutrition.

Biologics are approved for moderate-to-severe IBD in South Africa but are expensive in the private sector (R8,000–R25,000 per infusion). Medical aids with IBD CDL (Chronic Disease List) registration must cover approved biologics. Biosimilars (infliximab biosimilars) are cheaper and available in South Africa, offering comparable efficacy.

Nutritional Deficiencies to Monitor

IBD patients in South Africa should have annual blood work to screen for common deficiencies that affect energy, metabolism, and ability to exercise:

Iron and ferritin: Chronic gut blood loss in UC, and reduced absorption in Crohn's, make iron deficiency anaemia very common. This causes fatigue that makes exercise impossible — treat it first.
Vitamin B12: Absorbed in the terminal ileum — the part of the small intestine most commonly resected in Crohn's. Crohn's patients with ileal involvement or resection need B12 supplementation.
Vitamin D: Deficiency is paradoxically common in sunny South Africa among IBD patients due to reduced time outdoors during flares, reduced absorption, and low dietary fat intake. Supplement 1,000–2,000 IU vitamin D3 daily.
Zinc: Lost via diarrhoea. Zinc deficiency impairs immune function, wound healing, and taste — exacerbating poor appetite.
Calcium: Corticosteroid use and reduced dairy intake increase osteoporosis risk. Ensure adequate calcium through low-fat dairy, fortified plant milks, or supplements.

Exercise With IBD in South Africa

Exercise is safe and beneficial during remission but must be calibrated to disease activity:

During remission: aim for 150 minutes of moderate activity per week. Walking, swimming, cycling, yoga, and resistance training are all appropriate.
During mild flares: gentle walking is fine; avoid high-intensity exercise that diverts blood flow from the gut and can worsen symptoms.
During severe flares: rest. The inflammatory burden is high — exercise is not the priority.
Pilates and yoga are particularly useful for IBD patients as they improve core strength, reduce stress (a major flare trigger), and are gentle on the gut.
Many SA municipal gyms and Virgin Active locations offer low-intensity classes suitable for IBD patients in remission.

IBD Resources in South Africa

GESA (Gastroenterology Society of South Africa) — gesa.org.za — specialist directory and guidelines
Crohn's and Colitis South Africa (CCSA) — crohnsandcolitis.co.za — patient support organisation
ADSA (Association for Dietetics in South Africa) — adsa.org.za — find a registered dietitian with GI experience
IBD is a PMB condition in South Africa — your medical aid must cover gastroenterologist consultations, diagnostics, and approved medications
Academic hospital IBD clinics: Groote Schuur (UCT), Chris Hani Baragwanath, Charlotte Maxeke (Wits), Tygerberg (SU), Inkosi Albert Luthuli (UKZN)

Frequently Asked Questions

Can I lose weight with Crohn's disease?

Yes — during remission, moderate calorie reduction with a Mediterranean-style diet is safe. Avoid aggressive restriction. During active flares, weight loss is not the goal — nutritional support is.

Why am I gaining weight on prednisolone for UC?

Prednisolone causes fluid retention, increased appetite, and fat redistribution — this is a pharmacological effect, not a lifestyle failure. Reducing sodium, increasing protein, and gentle exercise can limit gain. The weight typically reverses once steroids are tapered.

Is biltong safe with IBD?

During remission, plain low-fat biltong in moderate quantities is generally well-tolerated — it is high-protein and low-carbohydrate. Avoid heavily spiced varieties. During flares, avoid biltong as it is tough and can irritate the gut.

Are biologics safe for weight management?

Biologics do not directly cause weight gain. They improve remission rates dramatically, which may lead to restored appetite and weight gain — but this is vastly preferable to ongoing active disease and undernutrition.

This article is for informational purposes only and does not constitute medical advice. IBD management should be guided by a gastroenterologist and registered dietitian. Always consult your doctor before changing your diet during active disease.