Dietary Fiber Content of Nigerian Staple Foods and Its Public Health Implications: A Systematic Review

Background Dietary fiber is an essential component of a healthy diet, associated with reduced risk of cardiovascular disease, type 2 diabetes, obesity, and colorectal cancer. In Nigeria, the nutrition transition—shifting from traditional high-fiber staples to refined, low-fiber foods—has accelerated the burden of non-communicable diseases (NCDs). However, comprehensive data on the fiber content of commonly consumed Nigerian staples are scattered, and public health messaging around fiber remains weak. Objective This review synthesizes available evidence on the dietary fiber content of major Nigerian staple foods (cassava, yam, maize, rice, sorghum, millet, plantain, sweet potato, and their processed products) and discusses the public health implications for NCD prevention. Methods A systematic search of PubMed, Scopus, ScienceDirect, Google Scholar, and ResearchGate was conducted for studies published between 2000–2026 following PRISMA guidelines. Included studies reported crude or dietary fiber content of Nigerian staples. Data were extracted and presented in comparative tables, and findings were integrated within current dietary guidelines and NCD epidemiology in Nigeria. Results Unprocessed staples vary widely in fiber content: whole grains (sorghum: 6–10%; millet: 7–12%; maize: 2–4%), roots/tubers (sweet potato: 2.5–3.5%; cassava root: 1.5–2.5%; yam: 1.5–2.5%; plantain: 2–4%). Processing reduces fiber markedly: white rice (0.4–1.0%), cassava garri (1.5–3.0%), yam flour (1.0–2.0%), and maize meal (1.0–2.0%). Traditional fermentation and retention of bran/peels increase fiber content. Current estimated daily fiber intake among Nigerian adults (10–15 g/day) falls below the recommended 25–30 g/day. Low fiber intake is associated with rising NCD prevalence: diabetes (5.8% adults), hypertension (32%), and colorectal cancer (increasing incidence). Conclusion Nigerian diets are becoming dangerously low in fiber due to reliance on refined staples. Promoting consumption of whole grains, unprocessed roots/tubers, and fiber-retaining processing methods (e.g., sweet potato garri, unpeeled yam flour) is a cost-effective public health strategy. Food-based dietary guidelines should include explicit fiber targets and encourage diversification of carbohydrate sources.