The Volumetric Loophole: Why 'Less Sugar' Comparative Claims and Deceptive GDA Metrics on 500ml and 600ml Soft Drinks Exacerbate Population-Level Obesity and Dental Caries in Nigeria

Abstract Background The commercial food environment in urban Nigeria is driving a dual increase in diet-related non-communicable diseases (NCDs), particularly adult and early-onset childhood obesity, alongside severe dental caries. Beverage manufacturers are increasingly using front-of-pack nutrient comparative claims, such as "less sugar," alongside industry-led Guideline Daily Amount (GDA) panels to capture health-conscious demographics. While these labels are technically legal by achieving a relative 25% sugar reduction against outdated high-sugar baselines, this standard completely ignores the absolute sugar payload delivered by expanded 500ml and 600ml retail configurations. Objective To evaluate how commercial soft drinks in Nigeria carrying "less sugar" profiles (Coca-Cola, Pepsi, and 7-Up) align with or undermine the World Health Organization (WHO) guidelines for free sugar intake, and to model their direct contribution to the national burdens of obesity and dental caries. Methods A public health nutritional modeling and dietary intake assessment was conducted. The absolute free sugar masses for Coca-Cola (7.5 g/100ml), Pepsi (7.1 g/100ml), and 7-Up (6.9 g/100ml) were mapped across 500ml and 600ml bottles. These payloads were benchmarked against the WHO recommendation restricting free sugars to < 10% (strong recommendation) and < 5% (conditional recommendation) of daily energy intake for a standard 2,000 kcal/day adult profile (ceiling: 50 g/day) and a 1,500 kcal/day pediatric profile (ceiling: 37.5 g/day). Front-of-pack industry’s 250ml GDA baseline was mathematically evaluated against WHO absolute thresholds to expose the scale of risk under-reporting. Results The evaluated soft drinks deliver absolute sugar payloads ranging from 34.5 g to 37.5 g per 500ml container, and 41.4 g to 45.0 g per 600ml container. A single 600ml bottle of 7-Up (6.9 g/100ml)—the lowest concentration evaluated—delivers 41.4 g of absolute sugar, instantly exhausting 82.8% of an adult's and 110.4% of a child’s maximum daily allowance. For Coca-Cola, a single 600ml bottle delivers 45.0 g of sugar (90.0% of the adult and 120.0% of the pediatric daily limit). The industry’s GDA label asserting that a 250ml serving contains 19g of sugar or "21% GDA" relies on an unscientific 90g daily denominator. This under-reports obesity and dental risks by more than double, as 19g actually consumes 38.0% of an adult's and 50.7% of a child’s entire daily allowance. Conclusion Relative "less sugar" descriptors on large-volume containers mask dangerously large quantities of free sugars, creating a false sense of dietary safety that directly accelerates obesity and enamel demineralization across Nigerian demographics. The National Agency for Food and Drug Administration and Control (NAFDAC) must prohibit relative nutrient comparative claims on large-volume packaging and replace confusing GDA panels with mandatory front-of-pack black octagonal warning labels.