Bad fats include industrial-made trans fats. Trans fats consist of fat molecules that have been changed and deformed during a process of hydrogenation – heating oil and combining it with hydrogen.

While these fats are less likely to spoil and become more stable after hydrogenation, they are extremely harmful for our health. Trans fats increase the amount of bad cholesterol in our bodies and lower the amount of good cholesterol, increasing your risk of diabetes, stroke and heart disease. Basically, there's no safe amount of trans fats, and they should be completely avoided. Check food labels and skip any food containing partially hydrogenated oil. Also, choose to bake, roast and grill foods at home instead of frying.

Here are groups of products to avoid completely: fried foods (fried chicken, chicken nuggets, French fries), solid fats (vegetable shortenings, stick margarine), commercially baked goods (cakes, cookies, muffins, pizza dough, crackers, enriched breads, e.g. hamburgers buns) and pre-mixed products (chocolate milk, cake mix).