This updated guide explains fat's roles, how the body uses fats during activity, and the main fat types - saturated, monounsaturated, polyunsaturated (including omega-3s), and trans fats. It replaces the older one-size-fits-all advice with current recommendations: prioritize unsaturated fats (olive oil, nuts, avocados, fatty fish), limit saturated fat (about <10% of calories for most people), and avoid partially hydrogenated oils. Practical tips include two weekly servings of fatty fish or an EPA/DHA supplement and choosing whole-food swaps for saturated sources.

Why dietary fats matter

Fats are an essential nutrient. They store energy, cushion and protect organs, help regulate body temperature, and support cell membranes and brain function. Some fats also carry fat-soluble vitamins (A, D, E, K) and supply essential fatty acids your body cannot make.

How your body uses fat for fuel

Fuel mix depends on exercise intensity and duration. At low-to-moderate intensity, and during longer steady activity, the body relies more on fat. During high-intensity or short, all-out efforts, carbohydrates become the primary fuel. Both fuel systems work together; training, fitness level, and diet affect the balance.

The main types of dietary fat

Saturated fats

These tend to be solid at room temperature and are found in fatty meats, butter, cheese, cream, and some tropical oils (coconut, palm). Diets high in saturated fat raise LDL ("bad") cholesterol in many people. Current U.S. dietary guidance recommends limiting saturated fat (for most adults, keeping it to less than 10% of daily calories; lower targets apply for some with high LDL).

Unsaturated fats

These are liquid at room temperature and are generally heart-healthier. There are two subtypes:
  • Monounsaturated fats: found in olive oil, avocados, and many nuts.
  • Polyunsaturated fats: include omega-6 and omega-3 fatty acids; sources include vegetable oils, nuts, seeds, and fatty fish.
Omega-3s (EPA and DHA) from oily fish support heart and brain health; plant sources such as flaxseed and walnuts supply ALA, which the body partly converts to EPA/DHA but less efficiently.

Trans fats

Industrial trans fats (partially hydrogenated oils) increase heart disease risk and have been largely removed from the U.S. food supply, but it remains wise to read labels and avoid products listing "partially hydrogenated" oils.

Practical guidance for choosing fats

  • Favor unsaturated fats (olive oil, nuts, avocados, fatty fish) over saturated fats.
  • Replace foods high in saturated fat with whole-food alternatives rather than adding refined carbs.
  • Aim for at least two servings of fatty fish per week or consider an EPA/DHA supplement if you don't eat fish.
  • Keep overall fat intake within your daily calorie needs; fat is calorie-dense (9 kcal/gram).

Bottom line

Fats are necessary - but not all fats are equal. Prioritize unsaturated fats and omega-3 sources, limit saturated fats, and avoid industrial trans fats. Adjust choices to your health goals and, when needed, follow personalized advice from a registered dietitian or your clinician.

FAQs about Facts On Fats

Are all fats bad for you?
No. Unsaturated fats (monounsaturated and polyunsaturated) support heart and brain health. Saturated fats should be limited, and industrial trans fats avoided.
How much saturated fat should I eat?
Most U.S. guidance recommends keeping saturated fat under about 10% of daily calories; lower limits may be advised for people with high LDL cholesterol - talk with your clinician.
What are the best sources of omega-3 fats?
Fatty fish such as salmon, mackerel, sardines, and trout provide EPA and DHA. Plant sources (flaxseed, chia, walnuts) supply ALA, which converts to EPA/DHA only partially. Two servings of fatty fish per week is a common recommendation.
Should I use margarine or butter?
Choose spreads made from liquid vegetable oils (higher in unsaturated fats) and avoid products with partially hydrogenated oils. Read labels for trans fats and hydrogenated ingredients.
Can I take fish oil supplements instead of eating fish?
Supplements can provide EPA/DHA and are an option if you can't eat fish, but talk with a healthcare provider about dose, quality, and interactions with medications.

News about Facts On Fats

Know the facts about fats - Harvard Health [Visit Site | Read More]

Fats explained: saturated, unsaturated and trans fats - British Heart Foundation [Visit Site | Read More]

Trans-fat facts - The Statesman [Visit Site | Read More]

There's no reason to avoid seed oils and plenty of reasons to eat them - www.heart.org [Visit Site | Read More]

Types of Fat - The Nutrition Source [Visit Site | Read More]

How to Understand and Use the Nutrition Facts Label - fda.gov [Visit Site | Read More]

Dishing Out the Facts on Good Fats - Yahoo Finance [Visit Site | Read More]