The Big Three

How Macronutrients Fuel Your Body

What is fat?

Dietary fat is a nutrient that gives your body energy and helps you absorb vitamins like A, D, E, and K. Fat also helps build cell walls and make some hormones. [10,1]

Fats can be saturated or unsaturated. Unsaturated fats are often called the “healthier” choice.

Assorted high-fat foods including avocado, bacon, cheese, nuts, and peanut butter on a white background.
Blue plate with 6 groups of vitamins, a fork, and a knife on a beige background
Sunset over a cracked desert landscape

What can be bad about not getting enough fat?

Not enough fat (or not enough of the right fats) can lead to:

  • Trouble absorbing fat‑soluble vitamins (A, D, E, K).
  • Dry skin or feeling hungry often (fat helps with fullness).

[10]

What can be bad about getting too much fat?

Too much fat can be a problem mostly because fat is calorie‑dense. This can lead to:

  • Weight gain over time if total calories are too high.
  • Higher LDL (“bad”) cholesterol if the extra fat is mostly saturated fat.

[10,11]

White bathroom scale on a dark surface
Fork with a measuring tape wrapped around it on a yellow background

Food examples (Fats)

Saturated fat

Saturated fat is found in many animal foods (like butter, cheese, and fatty meats) and some tropical oils (like coconut and palm). [11]

Many guidelines suggest limiting saturated fat by replacing it with unsaturated fats. [12,13,11]

What can be bad about too much saturated fat?

Too much saturated fat can raise LDL cholesterol, which can raise the risk of heart disease over time. [10,11]

Examples of saturated‑fat foods

Food

Typical serving size

Saturated fat (g)

Butter

1 tablespoon (14 g)

7.3 g

Cheddar cheese

1 ounce (28 g)

5.4 g

Whole milk

1 cup (244 g)

4.6 g

Cream cheese

1 tablespoon (15 g)

2.9 g

Heavy cream

1 tablespoon (15 g)

3.5 g

Vanilla ice cream

1/2 cup (66 g)

4.5 g

Cooked bacon (pan-fried)

36 g (about 3 slices)

4.3 g

Pork sausage

1 link (23 g)

2.8 g

Ground beef (80% lean / 20% fat, raw)

4 oz (113 g)

8.6 g

Coconut oil

1 tablespoon (14 g)

11.2 g

Beef tallow

1 tablespoon (13 g)

6.4 g

Lard

1 tablespoon (13 g)

5.0 g

Dark chocolate (70–85% cocoa)

1 ounce (28 g)

7.0 g

Saturated‑fat amounts are typical estimates from USDA FoodData Central. [20]

Unsaturated fat

Unsaturated fats are found in foods like olive oil, nuts, seeds, avocado, and fish. Replacing saturated fat with unsaturated fat can help lower heart‑disease risk. [11]

Omega‑3 fats (a type of polyunsaturated fat) are important for health. Supplements can interact with some medicines and can raise bleeding risk for some people, so it’s smart to ask a clinician if you take a blood thinner. [14]

Food examples (unsaturated fats)

Food

Typical serving size

Unsaturated fat (g)

Olive oil

1 tbsp (14g)

11.27g

Canola oil

1 tbsp (14g)

12.80g

Peanut butter (smooth)

2 tbsp (32g)

10.26g

Almonds

1 oz (28g)

12.46g

Walnuts

1 oz (28g)

15.93g

Sunflower seeds (dry roasted)

1 oz (28g)

12.04g

Chia seeds

1 tbsp (10g)

2.57g

Flax seeds

1 oz (28g)

10.30g

Avocado

1 avocado (201g)

23.35g

Cooked Atlantic salmon (farmed)

3 oz (85g)

7.42g

Unsaturated‑fat amounts are typical estimates based on USDA FoodData Central data. [20]

References

References

Numbers in the text match this list. Accessed February 9, 2026.

  1. MedlinePlus (NIH). Nutrition. https://medlineplus.gov/nutrition.html

  2. CDC (NCHS). Nutrition (Health, United States): macronutrients and chronic disease risk. https://www.cdc.gov/nchs/hus/topics/nutrition.htm

  3. MedlinePlus (NIH). Carbohydrates. https://medlineplus.gov/ency/article/002469.htm

  4. MedlinePlus (NIH). Dietary Fiber. https://medlineplus.gov/dietaryfiber.html

  5. World Health Organization (WHO). Guideline: Sugars intake for adults and children (2015). https://www.who.int/publications/i/item/9789241549028

  6. USDA Nutrition Evidence Systematic Review (NESR). Sugar-sweetened beverages and risk of type 2 diabetes: systematic review (Nov 2024). https://nesr.usda.gov/sites/default/files/2024-11/Sugar-sweetened-beverages_type-2-diabetes-2025DGACSystematicReview.pdf

  7. CDC. About Cavities (Tooth Decay). https://www.cdc.gov/oral-health/about/cavities-tooth-decay.html

  8. American Heart Association (AHA). Whole grains, refined grains, and dietary fiber. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/nutrition-basics/whole-grains-refined-grains-and-dietary-fiber

  9. BMJ. Whole grain foods and risk of type 2 diabetes: meta-analysis summary. https://www.bmj.com/content/370/bmj.m2206

  10. MedlinePlus (NIH). Dietary fats explained. https://medlineplus.gov/ency/patientinstructions/000104.htm

  11. American Heart Association (AHA). Fats in Foods. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/fats-in-foods

  12. USDA Food and Nutrition Service (FNS). Dietary Guidelines for Americans (current edition). https://www.fns.usda.gov/cnpp/dietary-guidelines-americans

  13. MyPlate (USDA). More Key Topics: Oils, Added Sugars, Saturated Fats. https://www.myplate.gov/eat-healthy/more-key-topics

  14. NCCIH (NIH). Omega-3 supplements: what you need to know. https://www.nccih.nih.gov/health/omega3-supplements-what-you-need-to-know

  15. MedlinePlus (NIH). Protein in diet. https://medlineplus.gov/ency/article/002467.htm

  16. MyPlate (USDA). Protein Foods Group. https://www.myplate.gov/eat-healthy/protein-foods

  17. NIH Office of Dietary Supplements (ODS). Vitamin B12 fact sheet for consumers (PDF). https://ods.od.nih.gov/pdf/factsheets/VitaminB12-Consumer.pdf

  18. IARC (WHO). IARC Monographs evaluate consumption of red meat and processed meat (Press Release No. 240, 2015) (PDF). https://www.iarc.who.int/wp-content/uploads/2018/07/pr240_E.pdf

  19. National Kidney Foundation. CKD Diet: How much protein is the right amount?. https://www.kidney.org/kidney-topics/ckd-diet-how-much-protein-right-amount

USDA. FoodData Central (nutrition database). https://fdc.nal.usda.gov/