What are the most healthiest fats? A definitive guide

October 20, 2025 •

3 min read

According to the American Heart Association, replacing saturated and trans fats with unsaturated fats can help lower cholesterol and reduce the risk of heart disease. Understanding what are the most healthiest fats is crucial for anyone looking to improve their diet and overall well-being. These beneficial fats, found in various plant-based foods, fish, and nuts, play a critical role in cellular function and energy absorption.

Quick Summary

This guide explains the primary types of healthy fats, including monounsaturated and polyunsaturated fats, and details their significant health benefits. It provides a comprehensive list of the best food sources, offers practical dietary tips, and highlights the importance of fat quality over quantity for heart and brain health.

Key Points

Unsaturated Fats are Key: Monounsaturated and polyunsaturated fats are the healthiest types of dietary fat and should replace saturated and trans fats.
Heart-Healthy Monounsaturated Fats (MUFAs): Found in olive oil, avocados, and nuts, MUFAs help lower bad (LDL) cholesterol and reduce heart disease risk.
Essential Polyunsaturated Fats (PUFAs): Omega-3 and omega-6 fatty acids are essential, with omega-3s from fatty fish and plant sources being crucial for brain and heart health.
Avoid Industrial Trans Fats: These fats, found in many processed foods, significantly increase the risk of heart disease and stroke and should be avoided entirely.
Focus on Food Sources, Not Just Nutrients: The health effects of a fat depend on its source; a whole food like an avocado is healthier than highly processed foods, even with a similar fat profile.
Quality Over Quantity: All fats are high in calories, so while replacing unhealthy fats with healthy ones is beneficial, moderation and overall dietary balance are still crucial for weight management.

The Importance of Healthy Fats

Fat is a vital macronutrient that the body needs for energy, vitamin absorption, and hormone production. However, the type of fat consumed dramatically impacts one's health. While unhealthy fats like industrial trans fats can raise bad (LDL) cholesterol and increase cardiovascular disease risk, healthy unsaturated fats can improve cholesterol levels and reduce disease risk. Focusing on incorporating heart-healthy fats into your diet is a powerful step toward a healthier lifestyle.

Monounsaturated Fats: Heart Protection

Monounsaturated fats (MUFAs) have one unsaturated carbon bond in their molecular structure and are typically liquid at room temperature. They are known for their ability to lower bad (LDL) cholesterol while maintaining good (HDL) cholesterol, thereby reducing the risk of heart disease and stroke.

Common sources of MUFAs include:

Olive Oil: A cornerstone of the Mediterranean diet, especially extra virgin olive oil, which is also rich in antioxidants.
Avocados: A nutrient-dense fruit packed with MUFAs and fiber.
Nuts: Almonds, cashews, pecans, and hazelnuts are excellent sources.
Seeds: Pumpkin and sesame seeds contain a healthy dose of MUFAs.
Peanut Oil: A good cooking oil option.

Polyunsaturated Fats: Essential for Function

Polyunsaturated fats (PUFAs) have multiple unsaturated carbon bonds and are considered 'essential fats' because the body cannot produce them. These fats also help lower bad (LDL) cholesterol and come in two main types: omega-3 and omega-6 fatty acids.

Omega-3 Fatty Acids:

Marine Sources: The richest sources of the omega-3s EPA and DHA are fatty fish like salmon, mackerel, herring, and sardines. The American Heart Association recommends two servings of fatty fish per week.
Plant-Based Sources: ALA omega-3s are found in flaxseed, chia seeds, walnuts, and canola oil.

Omega-6 Fatty Acids:

Vegetable Oils: Corn, safflower, soybean, and sunflower oils are common sources.
Nuts and Seeds: Walnuts and sunflower seeds are rich in omega-6s.

Healthy Fats vs. Unhealthy Fats: A Comparison


Feature	Monounsaturated Fats (MUFAs)	Polyunsaturated Fats (PUFAs)	Saturated Fats	Trans Fats
State at Room Temp	Liquid	Liquid	Solid	Solid/Semi-solid (Industrial)
Sources	Olive oil, avocado, nuts	Fatty fish, flaxseed, walnuts	Red meat, butter, tropical oils	Processed and fried foods
Cholesterol Impact	Lowers LDL, maintains HDL	Lowers LDL, may raise HDL	Raises LDL, can increase heart risk	Raises LDL, lowers HDL significantly
Associated Health Risk	Lower risk of heart disease	Lower risk of heart disease	Increased risk of heart disease	High risk of heart disease and stroke

Practical Ways to Incorporate Healthiest Fats

Shifting your dietary habits from unhealthy to healthy fats is simpler than you might think. Small, consistent changes can have a significant impact on your health.

Switch Cooking Oils: Use olive oil, canola oil, or avocado oil for cooking instead of butter, shortening, or coconut oil.
Snack on Nuts and Seeds: Replace processed snacks with a handful of almonds, walnuts, or chia seeds.
Add Avocados: Include avocado in sandwiches, salads, or on toast for extra flavor and healthy fat.
Eat Fatty Fish: Aim for at least two servings of fatty fish like salmon or mackerel per week to get enough omega-3s.
Top with Flaxseed: Sprinkle ground flaxseed on oatmeal, yogurt, or salads for a boost of ALA omega-3s.

The Role of Fat in a Healthy Diet

While it’s clear that unsaturated fats are the most beneficial, it's important to remember that all fats are calorie-dense. Moderation is key, and replacing unhealthy fats with healthy ones is more effective than simply adding them to your diet. The overall quality of your diet matters more than avoiding fat entirely. For example, the saturated fat in whole foods like dark chocolate or full-fat Greek yogurt is metabolized differently than the saturated fats in highly processed baked goods.

Conclusion

Understanding what are the most healthiest fats is fundamental to modern nutrition. Monounsaturated and polyunsaturated fats, including essential omega-3s, offer proven benefits for heart and brain health by positively affecting cholesterol levels and reducing inflammation. By replacing harmful industrial trans fats and limiting saturated fats from processed foods, you can significantly enhance your health. Incorporating sources like olive oil, avocados, nuts, seeds, and fatty fish into your diet will provide your body with the beneficial fats it needs to thrive. A balanced approach focusing on the quality of fats, rather than just quantity, is the smartest strategy for long-term well-being. For further reading on dietary fat, the Harvard T.H. Chan School of Public Health's nutrition source is a valuable resource on the topic: https://nutritionsource.hsph.harvard.edu/what-should-you-eat/fats-and-cholesterol/.

Frequently Asked Questions

The most healthiest fats are unsaturated fats, which include monounsaturated and polyunsaturated fats. Monounsaturated fats are found in olive oil and avocados, while polyunsaturated fats (like omega-3s) are in fatty fish, flaxseed, and walnuts.

While the link between all saturated fat and heart disease is complex and debated, it is generally recommended to limit intake and replace it with unsaturated fats where possible. Replacing saturated fat with polyunsaturated fat can lower heart disease risk.

Trans fats are artificial fats created through a process called hydrogenation. They are the unhealthiest type of fat because they raise bad (LDL) cholesterol and lower good (HDL) cholesterol, increasing heart disease and stroke risk.

You can increase your omega-3 intake by eating fatty fish like salmon or mackerel twice a week. Plant-based sources include flaxseed, chia seeds, and walnuts, which contain the omega-3 ALA.

Simple swaps include using olive oil instead of butter for cooking, snacking on nuts or seeds instead of processed snacks, and adding avocado to salads or sandwiches.

Yes. All fats, including healthy ones, are high in calories. Consuming more calories than you burn can lead to weight gain, so healthy fats should be part of a balanced diet eaten in moderation.

Yes, healthy fats, particularly omega-3s, are crucial for brain health. Studies show that a higher intake of unsaturated fats from sources like olive oil and nuts is linked to better cognitive function.

Yes, there are three main types: ALA (found in plants like flaxseed), EPA, and DHA (found mainly in fatty fish). The body can convert some ALA into EPA and DHA, but not efficiently.

The US FDA advises that two to three servings of fish per week are safe and beneficial for most people. It's recommended to choose fish low in mercury, such as salmon, herring, or sardines, and limit consumption of high-mercury fish like king mackerel or swordfish.