In 2016, Chile did something most countries only talk about: it passed one of the world's most comprehensive food laws and actually measured whether it worked. The results, published in The Lancet and based on data from over 300,000 schoolchildren, suggest that a bold combination of warning labels, school sales bans, and marketing restrictions can bend the curve on childhood obesity—a problem that has made Chile one of the globe's worst offenders.
This matters because childhood obesity is not a problem that looks like it will solve itself. In Chile, before 2016, nearly half of girls and over half of boys in primary school were overweight or obese. The country ranks among the highest globally for childhood overweight and obesity rates, yet had limited evidence that anything could reverse it at scale. That changed when Chile's Food Labeling and Advertising Law, or FLAL, took effect. The law targets products high in sugar, saturated fat, salt, and calories through three simultaneous moves: black octagon warning labels on the front of packages, a ban on selling such products in schools, and restrictions on marketing junk food to children.
Eighteen months into the first phase of FLAL, girls in the same grade cohorts showed a 1.4 percentage point reduction in overweight or obesity risk—from 47.7% to roughly 46.3%—while boys saw a 1.2 percentage point drop from 52%. Even at six months, the trend was visible: girls had dropped by 0.9 percentage points and boys by 1.2 percentage points. These numbers may seem modest in isolation, but they represent real children, and they came remarkably fast.
Prof. Guillermo Paraje from Universidad Adolfo Ibáñez Business School, who led the research, notes this is groundbreaking territory. "Although individual national measures like sugar taxes on soft drinks have been associated with improved health outcomes, this is the first study to plausibly demonstrate that a package of policies can reduce early childhood overweight/obesity risk at the national level," Paraje says. The emphasis on "package" matters. One label alone might not move the needle. One school ban might not stick. But all three together, working on both supply and demand, seem to work.
What makes this particularly striking is the speed of impact. Children showed measurable improvement within months, not years. Dr. Nieves Valdes, Paraje's colleague, points out that even small reductions in childhood weight carry outsized long-term benefits. "Even a small weight reduction for children who have overweight or obesity is likely to bring meaningful long-term health benefits, given the strong links between childhood obesity and later risk of obesity, diabetes, hypertension and cardiovascular disease, as well as evidence that early prevention can substantially lower these risks."
The law didn't stop at Phase 1. Phases 2 and 3, introduced in 2018 and 2019, tightened limits even further, and early signs suggest the effect only grew—sales of labeled products dropped more sharply in Phase 2 than Phase 1. Chile's experiment suggests a path forward not just for a country wrestling with obesity, but for policymakers worldwide looking for proof that comprehensive, coordinated action on food policy actually works.