Saturated Fat

Saturated fat is known as the unhealthy or “bad” fat. Coconut oil has given saturated fat a makeover in recent years and many openly doubt the negative health effects associated with saturated fat. Some even go as far as touting it for its potential health benefits.

What is fat?

Dietary fat is one of the three macronutrients. Its main function is providing energy. Fat contains 9 calories per gram making it the most energy dense of the macronutrients. In addition to providing energy, fat also aids in the absorption of vitamins A, D, E, and K, builds cell membranes, surrounds some nerves, and produces hormones.

What is saturated fat?

Dietary fat is either saturated or unsaturated. Saturated fats are historically known as unhealthy. Saturated fat is solid at room temperature and found in animal products such as meat, dairy, and eggs. Coconut and palm oil are two vegetable sources of saturated fats.

What does recent research say about saturated fat?

Study 1: Reduction in saturated fat intake for cardiovascular disease (2015)1

This meta analysis looked at 15 studies and 59,000 individuals. The researchers were specifically looking at the effect of replacing saturated fats with polyunsaturated fats or carbohydrates. Researchers found that reducing saturated fat decreased the risk of a cardiovascular event by 17%. This reduction was mostly seen when polyunsaturated fat replaced saturated fat. The same reduction was not seen when carbohydrates or protein made the replacement.

Study 2: Clinical Outcomes of Dietary Replacement of Saturated Fatty Acids with Unsaturated Fat Sources in Adults with Overweight and Obesity (2017)2

This meta analysis looked at 8 studies and examined the effects of replacing saturated fats with unsaturated fats on blood lipids. Researchers found replacing saturated with unsaturated fat slightly reduced total cholesterol levels, however, LDL (bad) cholesterol and triglyceride levels were unaffected.

Study 3: Palm Oil Consumption Increases LDL Cholesterol Compared with Vegetable Oils Low in Saturated Fat (2015)3

When the food industry needed to move away from hydrogenated oils and trans fats, they turned to palm oil. Unfortunately, palm oil is a vegetable source of saturated fat. Studies are now beginning to show that palm oil poses many of the same health issues as trans fats.

This meta analysis looked at 32 studies. Researchers were interested in the effects of palm oil on blood lipids when compared to other vegetable oils. They found palm oil significantly increased LDL (bad) cholesterol. They also compared the effects of palm oil vs butter and found both had similar effects on cholesterol levels.

Study 4: A systematic review of the effect of dietary saturated and polyunsaturated fat on heart disease (2017)4

This review looked into 67 studies examining the effects of saturated fat on heart disease. Researchers concluded that replacing saturated with unsaturated fat lowered the risk of cardiovascular disease. They also found the same reduction when replacing saturated fat with unrefined, high quality carbohydrates.

How much saturated fat should I eat each day?

The current dietary guidelines recommend limiting saturated fat to less than 10% of overall intake. For example, if you consume 2,500 calories per day, no more than 250 calories or 28 grams should come from saturated fat5.

The Bottom Line

Recent research still says saturated fat is unhealthy and an excessive intake leads to cardiovascular disease. Researchers still recommend: 1) limiting saturated fat intake, and, 2) replacing saturated and trans fat with polyunsaturated fat (best substitution), unrefined carbohydrates, and monounsaturated fat.

References

  1. Hooper, L., & Martin, N. (2015). Reduction in saturated fat intake for cardiovascular diseaseCochrane Database of Systematic Reviews.
  2. Hannon, B. A., & Thompson, S. V. (2017). Clinical Outcomes of Dietary Replacement of Saturated Fatty Acids with Unsaturated Fat Sources in Adults with Overweight and Obesity: A Systematic Review and Meta-Analysis of Randomized Control TrialsAnnals of Nutrition and Metabolism, 71(1-2), 107-117.
  3. Sun, Y., & Neelakantan, N. (2015). Palm Oil Consumption Increases LDL Cholesterol Compared with Vegetable Oils Low in Saturated Fat in a Meta-Analysis of Clinical TrialsThe Journal of Nutrition, 145(7), 1549-1558.
  4. Clifton, P., & Keogh, J. (2017). A systematic review of the effect of dietary saturated and polyunsaturated fat on heart diseaseNutrition, Metabolism and Cardiovascular Diseases,27(12), 1060-1080.
  5. Dietary Guidelines 2015-2020. (2015). Retrieved from https://health.gov/dietaryguidelines/2015/guidelines/chapter-1/a-closer-look-inside-healthy-eating-patterns/
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