In this three-part series on evidence-based nutritional guidelines, we’re exploring choosing quality carbs, eating mostly plants and limiting the intake of certain fats—all as a cornerstone to minimizing your risk of chronic disease and living a longer and more joyful life.

One of the most damaging nutritional notions of all time has been the idea that ‘fat is bad’—primarily because processed food manufacturers turned ‘low fat’ and ‘nonfat’ into mass marketing campaigns and pushed food on the American people that had much greater amounts of sugar instead.

Diet purveyors emphasized carbohydrates in place of fats, and our convenience culture turned to high-sugar, highly processed carbs as the answer. There’s a marked difference between good-for-us fats (unsaturated fats) and bad-for-us fats (saturated fats), and it comes down to their nutritional benefits or lack thereof.

What types of fats should you limit in your diet?

The two types of fat we should avoid in our diet include saturated fat and trans fat.

We know saturated fat and trans fat are not good for us. The vast majority of saturated fats come from animal sources (think meat and dairy), and most are solid at room temperature (butter, cheese, lard, the fatty marbling in your steak). Saturated fats can raise the level of ‘bad’ (LDL) cholesterol in our blood, which increases the risk of heart disease and stroke.

Trans fats both raise LDL cholesterol and lower HDL cholesterol (that’s the good one). Eating trans fats increases the risk of heart disease and stroke and is associated with a higher risk of type 2 diabetes. Although there are some natural sources of trans fats, most are artificial, created by adding hydrogen to liquid vegetable oils to make them more solid. Food manufacturers, restaurants and fast food chains use them in processed foods because they’re cheap, they last a long time, and, let’s face it, taste really good!

The key differences between good and bad fats:

  • Bad fats, particularly trans fats and excessive saturated fats, can increase the risk of heart disease and other chronic conditions.
  • Good fats, such as unsaturated fats and omega-3 fatty acids, are associated with various health benefits, including improved heart health and reduced inflammation.

Reversing decades of conventional wisdom on fat is really, really hard, but here are ways to get started:

  • Read food labels. Look for “partially hydrogenated” among the ingredients to be aware of the types of fats in the foods you consume.
  • Avoid processed foods. If you don’t recognize something in the ingredient list as something you may use when you cook at home, try to choose something else less processed.
  • Cook with olive or canola oil. Don’t be afraid of using a drizzle of olive oil as a garnish to add flavor, a pleasing mouthfeel, and to increase satiety.
    When in doubt, a plant-based fat is healthier than an animal-based fat. See my previous article for making your diet more plant-forward.
  • Do not fear healthy fats, such as nuts and avocados. These are nutrient-dense, delicious whole foods that really fill you up and keep you from snacking on processed-carb snacks.
  • It doesn’t have to be all or none. In general, subbing saturated fats with unsaturated fats is better, but having a delicious creamy bowl of full-fat plain Greek yogurt with a few chocolate chips and a drizzle of honey is a fantastic treat and far healthier than a processed pastry full of trans fats or added sugars.

Remember that while there have been several decades of messaging telling us otherwise, all fats are not the same and not the enemy. Choosing foods with healthy fats can be more beneficial to your health than processed low- or fat-free options.

Be sure to read the other posts in our series to learn more ways to incorporate eating habit changes into your daily life.