Fat: The Misunderstood Macronutrient

The fat topic is highly debated and often misunderstood subject in the world of nutrition and health. While some people may view all fats as unhealthy and avoid them altogether, others may consume excessive amounts of fat without realizing the potential health consequences. However, the truth lies somewhere in between.

Fat is an essential macronutrient that plays a vital role in the body, and consuming the right types and amounts of fat is crucial for optimal health. In this article, we will explore the different types of fat, their functions in the body, and how to incorporate healthy fats into your diet for optimal health and well-being.

Is fat necessary for the human body?

Yes, fat is necessary for the human body. It is one of the three macronutrients, along with carbohydrates and protein, that the body needs in relatively large amounts to function properly. Fat provides the body with a concentrated source of energy, with 9 calories per gram, and also helps the body absorb and transport fat-soluble vitamins (A, D, E, and K) and other essential nutrients.

Fat also plays a structural role in the body, as it provides insulation and cushioning to organs and tissues, and helps to maintain healthy skin and hair. In addition, fat is a key component of cell membranes and is necessary for the proper functioning of the nervous system and hormone production.

While it is important to consume the right types and amounts of fat, a complete absence of fat in the diet can be detrimental to health.

Types of fat

There are several types of fat, which can be classified based on their chemical structure and properties. The main types of fat are:

Saturated fat: This type of fat is typically solid at room temperature and is commonly found in animal products such as meat, butter, cheese, and cream. Saturated fat has been linked to an increased risk of heart disease and should be consumed in moderation.
Unsaturated fat: This type of fat is typically liquid at room temperature and is found in plant-based foods such as nuts, seeds, avocados, and oils. Unsaturated fat is considered to be a healthier type of fat and can be further classified into two subtypes:
- a. Monounsaturated fat: This type of fat is found in foods such as olive oil, peanuts, and avocados. It has been linked to a decreased risk of heart disease when consumed in moderation.
- b. Polyunsaturated fat: This type of fat is found in foods such as salmon, flaxseeds, and walnuts. It includes essential fatty acids such as omega-3 and omega-6, which the body cannot produce on its own and must be obtained through the diet.
Trans fat: This type of fat is typically found in processed foods such as baked goods, fried foods, and snack foods. Trans fats are created by a process called hydrogenation, which turns liquid vegetable oils into solid fats. Trans fats have been linked to an increased risk of heart disease and should be avoided as much as possible.

In addition to the main types of fat mentioned above, there are a few other types of fat worth noting:

Omega-3 fatty acids: This type of polyunsaturated fat is found in fatty fish such as salmon, mackerel, and sardines, as well as in walnuts, flaxseeds, and chia seeds. Omega-3 fatty acids have been shown to have anti-inflammatory properties and may help to reduce the risk of heart disease, stroke, and certain types of cancer.
Omega-6 fatty acids: This type of polyunsaturated fat is found in foods such as vegetable oils, nuts, and seeds. While omega-6 fatty acids are important for the body, consuming too much of them relative to omega-3 fatty acids can lead to inflammation and an increased risk of chronic diseases.
Medium-chain triglycerides (MCTs): This type of fat is found in coconut oil and is metabolized differently than other types of fats. MCTs are quickly absorbed and converted into ketones, which the body can use for energy.

What are the differences between saturated, unsaturated, and trans fats?

Saturated, unsaturated, and trans fats are different types of dietary fats that have unique chemical structures and properties.

Saturated fats are typically solid at room temperature and come mainly from animal sources such as meat and dairy products, as well as some plant-based sources such as coconut oil and palm oil. They are called “saturated” because the carbon atoms in their molecular structure are fully saturated with hydrogen atoms. A diet high in saturated fats has been associated with an increased risk of heart disease and high cholesterol levels.

Unsaturated fats are typically liquid at room temperature and come mainly from plant-based sources such as vegetable oils, nuts, seeds, and fatty fish. They can be further categorized into two types: monounsaturated and polyunsaturated fats. Monounsaturated fats are typically found in foods such as olive oil, avocados, and nuts, while polyunsaturated fats are found in foods such as salmon, walnuts, and flaxseeds. A diet high in unsaturated fats has been associated with a reduced risk of heart disease and improved cholesterol levels.

Trans fats are a type of unsaturated fat that are created when liquid vegetable oils are partially hydrogenated, a process that makes them more solid and increases their shelf life. Trans fats have been shown to increase LDL (bad) cholesterol levels and decrease HDL (good) cholesterol levels, leading to an increased risk of heart disease. Many countries have banned or limited the use of trans fats in processed foods.

In general, you should limit intake of saturated and trans fats and to focus on consuming more unsaturated fats as part of a healthy diet.

Monounsaturated versus polyunsaturated fats

Monounsaturated and polyunsaturated fats are two types of unsaturated fats that are beneficial for heart health. Here are some key differences between the two:

Monounsaturated fats: These are typically found in plant-based foods such as olive oil, avocado, and nuts. They have one double bond in their chemical structure, which makes them more stable than polyunsaturated fats. Monounsaturated fats can help lower LDL cholesterol levels and reduce the risk of heart disease.
Polyunsaturated fats: These are found in plant-based foods such as vegetable oils, nuts, and seeds, as well as in fatty fish such as salmon and mackerel. They have two or more double bonds in their chemical structure, which makes them less stable than monounsaturated fats. Polyunsaturated fats are important for brain function, reducing inflammation, and regulating blood sugar levels. There are two types of polyunsaturated fats: omega-3 and omega-6.
- Omega-3s are found in fatty fish and certain plant foods, and can help reduce inflammation and lower the risk of heart disease.
- Omega-6s are found in vegetable oils and processed foods, and can promote inflammation when consumed in excess.

Both monounsaturated and polyunsaturated fats are healthier options than saturated and trans fats. Consume a balance of both types of unsaturated fats as part of a healthy diet. The American Heart Association recommends that unsaturated fats should make up the majority of daily fat intake, with saturated fats limited to less than 6% of total daily calories.

Fat homeostasis

Fat homeostasis refers to the regulation of fat storage and metabolism in the body to maintain a balance between fat intake and fat use. It involves a complex interplay of hormones, enzymes, and other signaling molecules that work together to control the storage and breakdown of fat.

When we consume more fat than we need for energy, the excess is stored as triglycerides in adipose tissue. When energy is needed, hormones such as glucagon and adrenaline signal the breakdown of triglycerides into free fatty acids, which can be used by cells for energy production.

At the same time, hormones such as insulin and leptin regulate fat storage and metabolism by controlling the uptake and release of fatty acids from adipose tissue. Insulin promotes fat storage by stimulating the uptake of glucose and fatty acids into adipose tissue, while leptin signals the brain to reduce food intake and increase energy expenditure when fat stores are high.

Disruptions in fat homeostasis can lead to conditions such as obesity, insulin resistance, and metabolic syndrome. A diet high in saturated and trans fats, combined with a sedentary lifestyle, can lead to excess fat storage and disrupt the balance between fat intake and use. Conversely, a diet high in healthy unsaturated fats, combined with regular physical activity, can help maintain healthy fat homeostasis and reduce the risk of metabolic disorders.

Health benefits of fat

Healthy fats, when consumed in moderation, can provide a number of health benefits. Here are a few:

Improved heart health: Consuming healthy fats, such as monounsaturated and polyunsaturated fats, has been linked to a reduced risk of heart disease. This may be due in part to their ability to lower LDL (bad) cholesterol levels and increase HDL (good) cholesterol levels.
Improved brain function: Fat is an important component of brain tissue and is necessary for proper brain function. Consuming healthy fats, such as omega-3 fatty acids, has been linked to improved cognitive function and a reduced risk of age-related cognitive decline.
Reduced inflammation: Omega-3 fatty acids have anti-inflammatory properties and may help to reduce inflammation in the body. Chronic inflammation is associated with a number of health conditions, including heart disease, diabetes, and certain types of cancer.
Improved nutrient absorption: Many vitamins and minerals, such as vitamins A, D, E, and K, are fat-soluble, which means they require fat to be properly absorbed and utilized by the body. Consuming healthy fats along with nutrient-rich foods can help to improve nutrient absorption.
Increased satiety: Fat is more satiating than carbohydrates and protein, which means it can help to keep you feeling fuller for longer. Incorporating healthy fats into your meals can help to reduce hunger and prevent overeating.

Health risks of fat

While consuming healthy fats in moderation can have health benefits, consuming too much of certain types of fats, or consuming unhealthy types of fats, can have negative health effects. Here are some health risks associated with excessive or unhealthy fat intake:

Increased risk of heart disease: Consuming too much saturated and trans fats can increase LDL (bad) cholesterol levels and increase the risk of heart disease. High levels of LDL cholesterol can contribute to the formation of plaque in the arteries, which can lead to heart attacks and strokes.
Weight gain and obesity: Consuming too many calories from any source, including fat, can lead to weight gain and obesity. High-fat diets can be calorie-dense, and consuming too much fat without balancing calorie intake with physical activity can lead to weight gain.
Increased risk of certain cancers: Some studies have linked high intake of certain types of fat, such as saturated fat, with an increased risk of certain cancers, such as breast, prostate, and colorectal cancer.
Increased risk of type 2 diabetes: Consuming a high-fat diet, particularly one high in saturated fat, has been linked to an increased risk of type 2 diabetes.
Increased risk of liver disease: Consuming a diet high in saturated and trans fats can contribute to the development of non-alcoholic fatty liver disease (NAFLD), a condition in which excess fat accumulates in the liver and can lead to liver damage.

What is the daily recommended intake of fat?

The daily recommended intake of fat varies depending on age, sex, weight, and physical activity level. However, the American Heart Association provides the following guidelines for daily fat intake:

Total fat intake: For adults, 20-35% of total daily calories should come from fat. For example, if you consume 2000 calories per day, 400-700 of those calories should come from fat.
Saturated fat intake: Saturated fat should be limited to less than 10% of total daily calories. For example, if you consume 2000 calories per day, less than 200 of those calories should come from saturated fat.
Trans fat intake: Trans fat intake should be kept as low as possible, ideally at 0 grams per day.

The quality of the fat source matters. Instead of focusing on just meeting the recommended daily intake, focus on incorporating healthy sources of fat into your diet, such as nuts, seeds, fatty fish, and plant oils, while limiting unhealthy sources of fat, such as processed and packaged foods that often contain unhealthy types of fat. Also, balance calorie intake with physical activity to maintain a healthy weight and reduce the risk of chronic diseases.

Fat and obesity

Obesity is a complex condition that can have multiple causes, including genetics, lifestyle, and environmental factors. Consuming too many calories, including from fat, can contribute to weight gain and increase the risk of obesity. However, not all types of fat have the same effect on weight gain.

Research has shown that diets high in saturated and trans fats may be linked to an increased risk of obesity and weight gain, while diets high in healthy fats, such as monounsaturated and polyunsaturated fats, may be associated with a lower risk of obesity.

In addition to the type of fat consumed, the overall calorie intake and physical activity level also play a significant role in weight management. Consuming excessive calories from any source, including carbohydrates and protein, can lead to weight gain if calorie intake exceeds energy expenditure.

To maintain a healthy weight and reduce the risk of obesity, it’s important to focus on a balanced diet that includes a variety of nutrient-dense foods, including healthy sources of fat, while limiting processed and packaged foods that are high in unhealthy fats and calories. Regular physical activity can also help to balance calorie intake and promote weight management.

Fat and cholesterol

Fat intake can affect cholesterol levels, particularly the levels of LDL cholesterol, which is often referred to as “bad” cholesterol. High levels of LDL cholesterol can increase the risk of heart disease and stroke. Here’s how fat intake can affect cholesterol levels:

Saturated fats: Saturated fats, which are commonly found in animal products such as meat, dairy, and butter, can raise LDL cholesterol levels. It is recommended to limit intake of saturated fats to less than 10% of total daily calorie intake.
Trans fats: Trans fats are artificially produced fats that are often found in processed foods such as baked goods, fried foods, and snack foods. Trans fats can raise LDL cholesterol levels and lower HDL (good) cholesterol levels. It is recommended to avoid trans fats as much as possible.
Unsaturated fats: Unsaturated fats, which are found in foods such as nuts, seeds, avocado, and fatty fish, can help lower LDL cholesterol levels when consumed in moderation. Polyunsaturated fats, such as omega-3 and omega-6 fatty acids, are particularly beneficial for heart health.

Fat and cancer

Research has suggested that a diet high in saturated and trans fats may increase the risk of certain types of cancer, including colon, breast, and prostate cancer. However, the link between fat intake and cancer is complex and not fully understood. Here are some possible mechanisms by which fat intake may affect cancer risk:

Obesity: A high-fat diet can lead to weight gain and obesity, which is a known risk factor for many types of cancer.
Inflammation: A diet high in saturated and trans fats can increase inflammation in the body, which can promote the growth of cancer cells.
Hormones: Some types of cancer, such as breast and prostate cancer, are hormone-sensitive, meaning they are affected by levels of certain hormones in the body. Fat intake may affect hormone levels, which can in turn affect cancer risk.

On the other hand, some types of fats, such as omega-3 fatty acids, have been shown to have anti-inflammatory properties and may help reduce the risk of certain types of cancer. More research is needed to fully understand the relationship between fat intake and cancer, but in general, you should limit intake of saturated and trans fats and focus on consuming healthy unsaturated fats as part of a balanced diet. Additionally, maintaining a healthy weight, being physically active, and consuming a variety of fruits, vegetables, and whole grains can also help reduce the risk of cancer.

Can a high-fat diet improve athletic performance?

There is some evidence to suggest that a high-fat, low-carbohydrate diet (also known as a ketogenic diet) may improve athletic performance in certain situations, particularly in endurance sports. This is because the body can use fat as a fuel source during exercise when glycogen (stored carbohydrates) levels are depleted.

Research has shown that a ketogenic diet may increase fat oxidation during exercise, which can lead to better endurance performance. However, the optimal diet for athletic performance can vary depending on the individual’s sport, goals, and training regimen. For high-intensity activities that rely on carbohydrate metabolism, a high-fat diet may not be as effective.

Additionally, there are potential drawbacks to following a high-fat diet, such as nutrient deficiencies and the risk of consuming too much saturated and trans fats. Work with a healthcare professional or registered dietitian to determine the most appropriate nutrition plan for individual needs and goals, including athletic performance.

How can I incorporate healthy fats into my diet?

Incorporating healthy fats into your diet is important for overall health and can be done in several ways. Here are some tips:

Choose healthy cooking oils: Swap out vegetable oils, such as corn or soybean oil, for healthier options such as olive oil, avocado oil, or coconut oil. These oils are high in monounsaturated and/or polyunsaturated fats and can be used for cooking, baking, or as a salad dressing.
Add nuts and seeds: Nuts and seeds are a great source of healthy fats. Try adding a handful of almonds or walnuts to your morning cereal or oatmeal, sprinkle chia seeds or flaxseeds on your yogurt or smoothie, or make your own trail mix with a variety of nuts and seeds.
Eat fatty fish: Fatty fish such as salmon, tuna, or mackerel are rich in omega-3 fatty acids, which are important for heart health. Try adding a serving of fish to your weekly meal plan or consider taking a fish oil supplement.
Include avocados: Avocados are high in monounsaturated fats and are a versatile food that can be added to many dishes. Mash up an avocado and use it as a spread on toast, add slices to your sandwich or salad, or make guacamole as a dip for vegetables.
Choose whole foods: Whole foods such as fruits, vegetables, and whole grains are naturally low in fat but can still provide small amounts of healthy fats. Try adding sliced avocado or a drizzle of olive oil to your salad, or add some nuts or seeds to your oatmeal or yogurt.
Use nut butters: Nut butters such as almond, peanut, or cashew butter are a delicious and easy way to add healthy fats to your diet. Spread some on apple slices or toast, add it to your smoothie, or use it as a dip for vegetables.
Snack on olives: Olives are high in healthy monounsaturated fats and are a great snack option. Add them to your charcuterie board or enjoy them on their own as a snack.
Choose lean sources of protein: While animal products are a source of healthy fats, they can also be high in saturated fats. Choose leaner cuts of meat, such as chicken or turkey breast, or opt for plant-based sources of protein such as tofu or beans.
Make your own salad dressing: Store-bought salad dressings can be high in unhealthy fats and added sugars. Make your own salad dressing using olive oil, vinegar, and herbs for a healthier alternative.
Bake with healthier fats: Swap out butter or margarine for healthier fats such as avocado or coconut oil when baking. This can help reduce the amount of saturated fat in your baked goods.

How do different cooking methods affect the fat content of food?

Different cooking methods can affect the fat content of food in different ways. Here are some examples:

Grilling or broiling: When grilling or broiling meat, the fat drips off into the flames or the drip tray, reducing the overall fat content of the meat.
Frying: When food is fried, it is typically cooked in oil, which can increase the fat content of the food. However, if the oil is not hot enough, the food can absorb more oil and become greasier.
Baking or roasting: When food is baked or roasted, some of the fat can be rendered out of the food, reducing the overall fat content. This is especially true for meat with a higher fat content.
Boiling or poaching: When food is boiled or poached, the fat content is generally not affected, unless the food is cooked in a fatty liquid.
Microwaving: When food is microwaved, the fat content is generally not affected, although some fat may be lost if the food is covered and the steam is allowed to escape.

Overall, the cooking method used and the type and amount of fat used in cooking can affect the fat content of food. Choosing healthy cooking methods, such as grilling, baking, or boiling, and using healthy fats in moderation, such as olive oil or avocado oil, can help to reduce the overall fat content of meals.

What to look for in the Nutrition Facts label on food items to help me make healthier choices on fat?

Pay attention to the Nutrition Facts label for the fat content of a food product, by following these steps:

Look for the serving size: The serving size is listed at the top of the label and represents the amount of food that is considered one serving. Make sure to check the serving size to determine how much of the food you are actually consuming.
Check the total fat content: The total fat content is listed in grams under the “Total Fat” heading. This represents the total amount of fat in one serving of the food product.
Look for specific types of fat: Under the “Total Fat” heading, the label may also list the amount of saturated fat and trans fat in the product. Saturated and trans fats can be harmful to health, so limit intake of these fats.
Look for healthy fats: Unsaturated fats, including monounsaturated and polyunsaturated fats, are beneficial for heart health and can help lower LDL cholesterol levels. Look for foods that are high in unsaturated fats and low in saturated and trans fats.
Use the percent daily value (%DV) to assess the fat content: The %DV is listed next to the total fat content and represents the percentage of the recommended daily intake for fat that one serving of the food product contains. The recommended daily intake for fat is typically 65 grams for adults on a 2,000 calorie diet. Aim to choose foods that have a %DV of 5% or less for saturated fat and 20% or more for healthy unsaturated fats.

How can I contact gastroenterologist Dr. Zavos for an appointment?

Dr. Chris Zavos is a board-certified gastroenterologist and hepatologist, located in Thessaloniki Greece, and specifically in Kalamaria suburb, about 7 kilometres (4 miles) southeast of downtown Thessaloniki. His private office is at: Fanariou 8 street (near Aigaiou and Adrianoupoleos avenues), Kalamaria (Thessaloniki), Greece.

Thessaloniki International Airport is only 10 km away from his private office in Kalamaria and can be reached by taxi within 13 minutes from the airport.

Dr. Chris Zavos performs endoscopies at Bioclinic private hospital in downtown Thessaloniki (Mitropoleos 86 street).

You can contact Dr. Zavos at phone numbers: (+30)-6976596988 and (+30)-2311283833, or you can email him at czavos@ymail.com. Dr. Zavos responds to Greek and English languages.