The World Health Organization (WHO) announced Monday a plan calling for countries around the world to ban the use of artificial trans fats — industrially-produced oils used in highly processed foods — over the next five years.
The United Nations agency estimates that half a million people die each year from heart disease caused by trans fats. The new plan is more of a step-by-step guide on how governments can eliminate artificial trans fats from the food supply by 2023. While the announcement is celebrated as a huge public health victory, trans fat is not the only dangerous fat you should watch out for.
What are trans fats?
Trans fatty acids are formed when hydrogen is added to vegetable oil to make it solid and stop it from turning rancid. Food companies use artificial trans fats — usually labeled as partially hydrogenated vegetable oil — in baked goods like cookies and crackers to lengthen their shelf life and for deep-frying. Back in the 1950s, people started filling their shopping carts with Crisco shortening and margarine, thinking they were a healthier alternative to the saturated fat in butter and lard. That’s before we knew better.
Why are trans fats bad for you?
Industrially-produced trans fat is the worst type of fat for your health. It raises your bad (LDL) cholesterol and lowers your good (HDL) cholesterol. It creates inflammation in the body, raising your risk of stroke, heart disease, diabetes, and a slew of other chronic illnesses. Trans fat can even impact your brain and lead to memory loss, reduced cognition, and depression.
Diets high in hydrogenated oils increase heart disease risk by 21 percent and deaths by 28 percent, says WHO.
“Why should our children have such an unsafe ingredient in their foods?” WHO Director-General Dr. Tedros Adhanom Ghebreyesus said in a statement on Monday.
Countries like Denmark, the UK, and the US have already made strides to ban trans fats, but developing countries in Africa and Asia still use trans fats liberally in food products. The U.S. Food and Drug Administration (FDA) ruled in 2015 that artificial trans fats are unsafe and called for food manufacturers to stop selling products that contain them by June 2018 — next month. New York City barred the use of trans fats in restaurants back in 2007, a move that lowered the rate of heart attack and stroke by 6 percent.
Other fats to watch out for
Certain fats — like the saturated fat in grass-fed butter — are great for you. That’s why, on the Bulletproof Diet, 50-70% of your daily calories come from healthy sources of fat.
Trans fats aren’t the only fats you need to be careful with. Omega 6 fats are a type of polyunsaturated fat (PUFA) that’s essential to your survival, but can also cause inflammation and compete with the good omega 3s (another type of PUFA).
Americans tend to eat way more omega 6 fat than necessary, and too few omega 3s. You want to eat just enough omega 6s to function, and to balance them with lots of omega 3s. 
Related: The Bulletproof Guide to Omega 3 Vs. Omega 6 Fats
Here’s how to get a good balance going:
— Avoid processed vegetable and seed oils: The most common source of omega 6s is linoleic acid, found in corn oil, soybean oil, safflower oil, cottonseed oil, sunflower oil, and certain nuts and seeds. The American Heart Association insists these oils are good for you, but they don’t protect you from coronary heart disease, cardiovascular disease, stroke, or early death like the AHA claims. 
— Cook at low heat: Cooking at high heats, microwaving, or frying will oxidize the fats. Oxidized omega 6 damages your DNA, inflames your heart, and raises your risk for certain cancers. Eat food that is raw, steamed till al dente, or baked at 320 degrees or less.
— Know your oils’ smoke points: The smoke point of an oil is the temperature at which the oil starts to break down and produce harmful free radicals, and where fatty acids become oxidized. Don’t cook with extra-virgin olive oil or Brain Octane Oil — save those for dressing your food after cooking. Instead, cook with ghee and coconut oil.
— Eat foods rich in omega 3 fats: You want to eat fewer omega 6s to allow the omega 3s to do their job — build and strengthen your body. To balance the fat ratio, eat plenty of low-mercury fatty fish like wild sockeye salmon, and opt for grass-fed butter and meat.