Globally, approximately 39% of adults are overweight, according to the World Health Organization.

Consequently, people are getting sick. Really sick.

In one generation, people in Asia have gone from having some of the lowest rates of heart disease, obesity, and diabetes to some of the highest. And in Sub Saharan Africa, the number one cause of death in adults over 30 is cardiovascular disease. I know. That shocked me too.

This, global citizens, is the legacy of SAD. And by that, I mean the Standard American Diet.

In a brilliant TED Talk, New York Times writer and food journalist Mark Bittman explores the evolution of the Standard American Diet and paints a clear picture of how things got so messed up. In less than a century, Americans went from exclusively enjoying locally sourced home-cooked meals, to relying on fast food and tv-dinners, to yo-yo-ing between the ever changing array of fad diets. Now, a lot of Americans couldn't recognize real food if it hit them in the face (hint: it’s not made in lab or a processing facility).

Walk through a grocery store or rummage through the average American kitchen, and what you’ll find will likely be the same thing: tons of animal products and processed foods, and minimal produce, legumes, or healthy grains. This diet is literally killing Americans, and it’s sweeping the planet- as fast-food chains populate the globe and sugary drinks make their way to the world’s most remote villages.

If we know who the culprit is, you’ve got to wonder- why do people continue to eat the stuff that’s killing them?

Apart from the fact that it tastes good, (or at least that’s what we’ve trained our taste buds to think) there are a couple factors standing in the way of improved health and diet.

For one, healthy whole foods have become more expensive than processed foods and animal products (whole foods are foods that remain as close to their natural form as possible). People living in poverty need to get the most bang for their buck in the short term, even if that means health problems that will cost them in the long term.

Secondly, there’s a lot of confusion and misinformation about what makes a healthy diet. Mark Bittman touches on this in his TED Talk, if only briefly. Essentially, the people responsible for telling Americans what is healthy are many times the same people running large agribusiness.

That’s why many Americans believe they need to load up on meat and milk to be strong, when in fact an excess of animal products is what’s making people sick. (Experts recommend that adults eat just over half a pound of meat per week, and studies have shown that the countries that consume the most milk have highest fracture rates and the worst bone health).

Furthermore, fad-diets like low-fat, high-protein, or low-carb have led people to believe that by simply adding magical ingredients like fiber and removing evil ingredients like fat from their food it becomes healthy. Bittman makes this clear: it’s not the isolated components of whole foods that make them nutritious- it’s the whole foods themselves. (Lesson here is anything that says enriched this or reduced that is a load of crap).

In the sage words of Michael Pollan, the answer is clear:

Eat food. Not too much. Mostly plants.

The good news is that by adhering to this advice and living a healthier lifestyle, cardiovascular disease, diabetes and hypertension are completely preventable for at least 95% of people. However, this means nothing for people with limited means, who don’t have the privilege of choosing what food to feed their kids. To truly make a difference, governments must ensure their people have access to affordable, nutritious food, while promoting programs that support healthy living.