What are the two worst fats? A guide to trans and saturated fats

According to the World Health Organization, over 278,000 deaths each year can be attributed to the intake of industrially produced trans fats, which are widely considered one of the two worst fats. This article explores why trans fats and excessive saturated fats pose a significant risk to your health, impacting cardiovascular wellness and cholesterol levels.

Quick Summary

Trans fats and high intakes of saturated fats are the two most detrimental fats for health, raising bad cholesterol and increasing disease risk. This guide explains their impact on cardiovascular health and offers healthy alternatives for better dietary choices.

Key Points

• Trans Fats are Universally Harmful: Industrially produced trans fats, created through the hydrogenation of vegetable oils, are considered the worst type of fat due to their severe negative impact on cholesterol and inflammation.

• Excess Saturated Fat Raises LDL: High intake of saturated fats from sources like red meat, butter, and tropical oils can raise LDL ("bad") cholesterol, increasing the risk of heart disease.

• Context for Saturated Fat Matters: Newer research suggests that the health impact of saturated fats depends on the food source and overall dietary pattern, with dairy fats potentially having a different effect than processed meats.

• Focus on Unsaturated Fat Replacements: A cornerstone of a heart-healthy diet is replacing unhealthy fats with beneficial monounsaturated and polyunsaturated fats found in foods like olive oil, nuts, seeds, and fatty fish.

• Read Food Labels: To avoid artificial trans fats, always check ingredient lists for "partially hydrogenated oils". For saturated fat, compare products and choose those with lower percentages.

• The Diet as a Whole is Most Important: Rather than demonizing a single nutrient, focus on a balanced, whole-food-based eating pattern to support long-term health.

• Cooking Methods Influence Fat Intake: Opting for grilling, baking, or steaming over frying can significantly reduce your consumption of unhealthy fats.

Understanding the 'Bad' Fats: Trans and Saturated

For decades, fats have been viewed with suspicion in the nutrition world. While our bodies need fat for energy, vitamin absorption, and hormone production, the type of fat we consume makes all the difference. Health experts consistently point to two types of fats as the most harmful: industrially produced trans fats and excessive saturated fats. The impact of these fats on our health, particularly on our cardiovascular system, cannot be overstated.

The Problem with Industrially Produced Trans Fats

Trans fats, or partially hydrogenated oils, are the result of a manufacturing process called hydrogenation that turns liquid vegetable oils into solid fats. Food producers historically used this process because it was a cheap way to increase shelf life and improve the texture of processed foods. Unfortunately, the resulting trans fats have no known health benefits and are double trouble for your heart.

Why Trans Fats Are So Dangerous

• Harmful Cholesterol Effects: Trans fats raise low-density lipoprotein (LDL), or "bad" cholesterol, while simultaneously lowering high-density lipoprotein (HDL), or "good" cholesterol. This combination dramatically increases the risk of heart disease and stroke.
• Inflammation: They cause inflammation within the body, a reaction that has been linked to heart disease, stroke, and type 2 diabetes.
• Artery Clogging: By negatively affecting cholesterol, trans fats contribute to the buildup of plaque in the arteries, making them hard and narrow.

The Ban on Artificial Trans Fats

Given their significant health risks, the U.S. Food and Drug Administration (FDA) banned the use of partially hydrogenated oils in processed foods, with full enforcement taking effect in 2021. While this has dramatically reduced their presence in the American food supply, small amounts may still exist. Furthermore, in countries with less strict regulations, trans fats remain a serious concern. It is critical to read ingredient labels and avoid any product listing "partially hydrogenated oil".

The Controversy and Concerns with Saturated Fats

Saturated fats are another group of fats that have long been flagged as unhealthy. Unlike trans fats, saturated fats occur naturally in many foods, particularly animal products. They are typically solid at room temperature, such as butter and the fat on meat. A diet high in saturated fat can increase LDL cholesterol and raise the risk of heart disease.

The Nuance in the Saturated Fat Debate

Recent research has introduced nuance to the long-standing warnings against all saturated fats. Some studies suggest that the overall food source and dietary pattern are more important than focusing on saturated fat in isolation. For example, the saturated fat in dairy products may have a different effect than that from processed meat and baked goods. Despite this, health organizations like the American Heart Association continue to recommend limiting saturated fat intake, typically to less than 6% of daily calories, especially for those with high cholesterol.

Table: Trans Fats vs. Saturated Fats

Feature	Trans Fats (Artificial)	Saturated Fats (Excessive)
Source	Industrially produced (partially hydrogenated oils)	Primarily animal products (meat, dairy) and tropical oils (coconut, palm)
Physical State	Solid at room temperature	Typically solid at room temperature
Effect on LDL	Raises LDL ("bad") cholesterol significantly	Raises LDL ("bad") cholesterol
Effect on HDL	Lowers HDL ("good") cholesterol	Less clear effect, can lower slightly
Inflammation	Increases body-wide inflammation	Potential to influence inflammatory pathways
Health Consensus	Universally considered harmful; intake should be avoided	Recommended to be limited, but overall dietary context matters

Choosing Healthier Alternatives

Replacing bad fats with beneficial ones is one of the most effective dietary changes you can make. The best alternatives are unsaturated fats, which include monounsaturated and polyunsaturated fats. These fats can improve cholesterol levels, reduce inflammation, and support heart health.

How to Replace Unhealthy Fats

• Cook with Healthier Oils: Instead of butter, shortening, or coconut oil, use liquid vegetable oils like olive, canola, sunflower, or avocado oil for cooking and dressings.
• Embrace Nuts and Seeds: Sprinkle nuts (like walnuts or almonds) or seeds (flax, chia, sunflower) on salads, oatmeal, or snacks to boost your intake of healthy fats.
• Incorporate Fatty Fish: Eat fatty fish such as salmon, mackerel, and sardines at least twice a week to get a good dose of omega-3 fatty acids, a type of polyunsaturated fat.
• Select Lean Proteins and Dairy: Choose lean cuts of meat and skinless poultry, and opt for low-fat or fat-free dairy products.
• Read the Ingredients List: Look for "partially hydrogenated oil" and avoid products that contain it. Also compare saturated fat content between similar products to make a lower-fat choice.

Conclusion: Making Smarter Choices for Better Health

While fat is an essential part of our diet, the two worst fats—industrially produced trans fats and excessive saturated fats—pose serious health risks. Trans fats are universally condemned and should be eliminated, while saturated fat intake should be limited and considered within the context of an overall healthy diet. By consciously choosing unsaturated fats as a replacement and prioritizing whole, unprocessed foods, you can significantly improve your heart health and overall well-being. A diet that emphasizes fruits, vegetables, whole grains, and lean proteins, as endorsed by organizations like the American Heart Association, is your best defense against these harmful fats.

Key takeaways

• Trans Fats are Universally Harmful: Industrially produced trans fats, created through the hydrogenation of vegetable oils, are considered the worst type of fat due to their severe negative impact on cholesterol and inflammation.
• Excess Saturated Fat Raises LDL: High intake of saturated fats from sources like red meat, butter, and tropical oils can raise LDL ("bad") cholesterol, increasing the risk of heart disease.
• Context for Saturated Fat Matters: Newer research suggests that the health impact of saturated fats depends on the food source and overall dietary pattern, with dairy fats potentially having a different effect than processed meats.
• Focus on Unsaturated Fat Replacements: A cornerstone of a heart-healthy diet is replacing unhealthy fats with beneficial monounsaturated and polyunsaturated fats found in foods like olive oil, nuts, seeds, and fatty fish.
• The Power of Reading Labels: To avoid artificial trans fats, always check ingredient lists for "partially hydrogenated oils". For saturated fat, compare products and choose those with lower percentages.
• The Diet as a Whole is Most Important: Rather than demonizing a single nutrient, focus on a balanced, whole-food-based eating pattern to support long-term health.
• Cooking Methods Influence Fat Intake: Opting for grilling, baking, or steaming over frying can significantly reduce your consumption of unhealthy fats.

FAQs

Q: What are the two worst fats? A: The two worst fats for health are industrially produced trans fats (partially hydrogenated oils) and excessive intake of saturated fats found in animal products and some plant oils.

Q: How do trans fats harm the body? A: Artificial trans fats are particularly harmful because they raise LDL ("bad") cholesterol while lowering HDL ("good") cholesterol, contributing to clogged arteries, inflammation, and an increased risk of heart disease and stroke.

Q: Are all saturated fats equally bad? A: No, evidence suggests that the health effects of saturated fats can vary depending on their food source. Saturated fats from processed meats and sugary baked goods are considered more harmful than those from whole foods like dairy.

Q: Where are artificial trans fats typically found? A: Although largely banned in the U.S., trans fats used to be common in many commercially baked goods (cookies, cakes), fried fast foods, vegetable shortening, and stick margarine.

Q: How can I identify trans fats in packaged food? A: Look at the ingredient list for the words "partially hydrogenated oil." Even if the nutrition label states "0g trans fat," it might still contain small amounts if made with this ingredient.

Q: What are healthy alternatives to these bad fats? A: Healthy alternatives include monounsaturated and polyunsaturated fats found in olive oil, nuts, seeds, and fatty fish like salmon. Replacing unhealthy fats with these can improve cholesterol levels.

Q: What is the recommended daily limit for saturated fat? A: Health organizations like the American Heart Association recommend limiting saturated fat intake to less than 6% of total daily calories for those with high cholesterol. For a 2,000-calorie diet, this equates to about 13 grams per day.

Citations

• Healthline. Good fats, bad fats, and heart disease. Healthline. https://www.healthline.com/health/heart-disease/good-fats-vs-bad-fats
• Mayo Clinic. Trans fat is double trouble for heart health. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/trans-fat/art-20046114
• American Heart Association. The Skinny on Fats. American Heart Association. https://www.heart.org/en/health-topics/cholesterol/prevention-and-treatment-of-high-cholesterol-hyperlipidemia/the-skinny-on-fats
• World Health Organization (WHO). Trans fat. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/trans-fat
• Healthline. What Is Saturated Fat and Is It Unhealthy? Healthline. https://www.healthline.com/nutrition/saturated-fat

Frequently Asked Questions

What are the two worst fats?

The two worst fats for health are industrially produced trans fats (partially hydrogenated oils) and excessive intake of saturated fats found in animal products and some plant oils.

How do trans fats harm the body?

Artificial trans fats are particularly harmful because they raise LDL ("bad") cholesterol while lowering HDL ("good") cholesterol, contributing to clogged arteries, inflammation, and an increased risk of heart disease and stroke.

Are all saturated fats equally bad?

No, evidence suggests that the health effects of saturated fats can vary depending on their food source. Saturated fats from processed meats and sugary baked goods are considered more harmful than those from whole foods like dairy.

Where are artificial trans fats typically found?

Although largely banned in the U.S., trans fats used to be common in many commercially baked goods (cookies, cakes), fried fast foods, vegetable shortening, and stick margarine.

How can I identify trans fats in packaged food?

Look at the ingredient list for the words "partially hydrogenated oil." Even if the nutrition label states "0g trans fat," it might still contain small amounts if made with this ingredient.

What are healthy alternatives to these bad fats?

Healthy alternatives include monounsaturated and polyunsaturated fats found in olive oil, nuts, seeds, and fatty fish like salmon. Replacing unhealthy fats with these can improve cholesterol levels.

What is the recommended daily limit for saturated fat?

Health organizations like the American Heart Association recommend limiting saturated fat intake to less than 6% of total daily calories for those with high cholesterol. For a 2,000-calorie diet, this equates to about 13 grams per day.