Poor Diet More Deadly Than Smoking, Study Finds

The study suggests that a poor diet causes more deaths around the world than smoking.

Bill Griffith, on vacation from Chicago, Illinois, lights up a cigarette as he visits the beach.
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The study suggests that a poor diet causes more deaths around the world than smoking.

The harmful effects of smoking are well-documented, as are the effects of a poor diet. But which is worse? A new study published in The Lancet suggests that ignoring the needs of your body with a poor diet causes more deaths globally than smoking. In particular, the study aimed to examine the consumption of major foods and nutrients in people across 195 countries to determine what happens to mortality and morbidity rates from noncommunicable diseases that stem from a poor diet.

Each dietary risk factor is connected to a specific exposure definition. For example, a diet low in fruits is one risk factor, and its exposure definition is the average daily consumption of fruits — frozen, fresh, cooked, canned, or dried. There were 15 dietary risk factors in total, including diets low in calcium, high in sodium, and high in red meat.

Using estimates of how many diseases can be attributed to specific dietary risk factors in adults 25 years and up, the team connected this influence to main inputs like intake of each dietary factor, the level of consumption associated with the lowest mortality risk, and the effect size of the dietary factor on disease endpoint. From here, the team calculated the number of deaths and disability-adjusted life years (DALYs) — which is comprised of the years lost to disability, ill-health, or early death — connected to diet for each disease outcome.

The results of the study revealed that in 2017, most people weren’t getting enough foods and nutrients, while at the same time they were eating too many unhealthy foods and nutrients. Not only that, but unlike other risk factors, poor diet affects all people equally regardless of sex, age, and the sociodemographic factors of their location. And although the impact of dietary risk factors did vary by country, non-optimal intake of sodium, fruits, and whole grains was the cause of over 50 percent of deaths and 66 percent of DALYs that were attributable to diet.

The authors concluded that a poor diet causes more deaths around the world than smoking, which suggests a need for dietary improvements in nations around the world.

“Our findings show that suboptimal diet is responsible for more deaths than any other risks globally, including tobacco smoking, highlighting the urgent need for improving human diet across nations.”

Although issues like the dangers of sugar are often focused on the most in public discussion, the study suggests that the most significant dietary risk factors are diets low in grains, high in sodium, low in fruit, low in vegetables, low in nuts and seeds, and low in omega-3 fatty acids.

“This finding suggests that dietary policies focusing on promoting the intake of components of diet for which current intake is less than the optimal level might have a greater effect than policies only targeting sugar and fat, highlighting the need for a comprehensive food system interventions to promote the production, distribution, and consumption of these foods across nations.”