Trans fatty acids are formed when a liquid fat is changed into a solid fat through a process called hydrogenation. Many manufacturers use hydrogenated oils as an ingredient because it extends the shelf life and consistency of foods. Trans fat will raise levels of “bad” LDL cholesterol and decrease levels of “good” HDL cholesterol. There are no safe levels of trans fat to eat each day, so try to avoid trans fat completely. Even if a food is advertised as “trans fat free,” it can still contain small amounts of trans fat. Therefore, avoid foods that list partially hydrogenated oils as ingredients. Sources of trans fat include:
Monounsaturated fats are considered one of the healthiest types of fats to eat, and are the backbone of the Mediterranean diet. They are found in olives, olive oil, avocados, nuts, nut butters, as well as sesame oil, peanut oil, and canola oil. (Be aware that most Canola oil in the US and Canada is GMO unless specifically labeled as non-GMO or organic.)

Polyunsaturated fats are required for some of the normal body functions listed above, but the body can’t produce them so they must be obtained from foods. Omega 3 fatty acids are a type of polyunsaturated fat and can be found in cold-water high-fat fish like salmon, mackerel, and sardines, and in flaxseeds, chia seeds, walnuts, canola oil (again look for non-GMO or organic), and unhydrogenated soybean oil (also look for non-GMO or organic as most soy products in the US are GMO unless they specifically state non-GMO or organic.)  Omega 3’s are also found in some greens, including romaine, spinach, and arugula.  Note that the body only partially converts plant-based omega 3’s to DHA and EPA, which are found in cold-water fish
The overarching message is that cutting back on saturated fat can be good for health if people replace saturated fat with good fats, especially, polyunsaturated fats. (1, 15, 22) Eating good fats in place of saturated fat lowers the “bad” LDL cholesterol, and it improves the ratio of total cholesterol to “good” HDL cholesterol, lowering the risk of heart disease.
Meanwhile, the official unsaturated fat definition encompasses any type of fatty acid that contains at least one double bond within the chain. These fats are further classified as either a monounsaturated fat or polyunsaturated fat based on the number of double bonds they contain. Unsaturated fats can include foods like vegetable oils, nuts, seeds and fish.

Yes, you need fat in your diet! All three macronutrients – fats, carbohydrates, and protein – are incredibly important for the human body’s functioning. Fats are important for cellular and hormonal health, and unlike carbohydrates and protein, fats also provide our bodies with a layer of protection, literally insulating our organs and also helping keep a normal body core temperature.


Healthy fats are unsaturated fats that are found in fatty fish like salmon, avocados, nuts and seeds, plant oils that are liquid at room temperature like olive oil, and coconut oil. Coconut oil is contested as a healthy fat because it is a saturated fat, but because the majority of its fat content is medium-chain triglycerides (MCT), I consider them an exception.

The body is able to turn ALA into usable DHA and EPA to some degree, but this isn’t as efficient as getting DHA and EPA directly from food sources that provide it. Even after extensive research, it’s not totally clear how well ALA converts into EPA and DHA or if it has benefits on its own, but health authorities, like those at Harvard Medical School, still consider all sources of omega-3s crucial in the diet. (20)
Since sources of fat are more calorie-dense, it is important to understand what a serving of a fat is equivalent to. For example, one teaspoon of butter, margarine or mayonnaise is one fat serving. For times when you may not have a measuring spoon available, a visual equivalent of one teaspoon is the tip of your thumb. See below for examples of serving sizes for added fats.
Consuming high levels of calories – regardless of the source – can lead to weight gain or being overweight. Consuming high levels of saturated or trans fats can also lead to heart disease and stroke. Health experts generally recommend replacing saturated fats and trans fats with monounsaturated fats and polyunsaturated fats – while still maintaining a nutritionally-adequate diet.
Cutting back on saturated fat will likely have no benefit, however, if people replace saturated fat with refined carbohydrates. Eating refined carbohydrates in place of saturated fat does lower “bad” LDL cholesterol, but it also lowers the “good” HDL cholesterol and increases triglycerides. The net effect is as bad for the heart as eating too much saturated fat.
For years, only true diet detectives knew whether a particular food contained trans fat. This phantom fat was found in thousands of foods, but only those familiar with the “code words” partially hydrogenated oil and vegetable shortening knew when it was present. Fortunately, after a large body of research in the 1990s sounded the alarm on its deleterious health effects, a series of policy initiatives led to the near elimination of artificial trans fat in the U.S. food supply by 2018. However, the road to eliminating trans fat was not so straightforward, and outside the U.S. there’s still more work to be done. In many developing nations, trans fat intake remains high.Read more about the key research and policy initiatives shining the spotlight on harmful trans fats.
This blue-green alga, available in powders and supplements, is full of healthy omega-3s like EPA and DHA. Research shows that these forms of omega-3s are more active in the body than ALA at controlling inflammation and belly fat. Not only is spirulina a great source of heart-healthy fats, but it’s also super-rich in protein, a great source of probiotics, and may even be able to help flatten your belly during exercise.
In fact, while carbohydrates from whole grain, fiber-rich sources can be beneficial, refined carbohydrates found in foods like candies, white bread, baked goods and sweets provide little in terms of nutrition apart from extra calories and sugar. According to a study in the Journal of the American College of Cardiology, refined carb intake was associated with a higher risk of coronary heart disease while consumption of whole grains and polyunsaturated fats was linked to a lower risk. (6)
Remember pancreatic lipase from earlier in the duodenum? Well, lipoprotein lipase breaks down triglycerides for absorption which goes into the fat tissue for storage, or it’ll be absorbed in muscle tissue for energy. Where do the chylomicrons go? Basically, they shrink so much that they just become tiny little particles that used to be. They’re absorbed into the liver and then the liver metabolizes them. The liver is key for fat metabolism! Liver health = fat digestion efficiency = healthy fat burning potential.
Not only does dark chocolate taste great, but it’s also considered a superfood as well. It’s high in fat and rich in antioxidants, which help protect our bodies from disease-causing free radicals. The flavanols found in dark chocolate also improve heart health, thanks to their ability to lower blood pressure and get more blood flowing to the heart and the brain. (31) And if you’ve ever found that nibbling on a piece of chocolate helps you focus, you’re not alone. It’s a brain food that actually helps improve cognitive performance. (32)

Often thought of as a high-fat food, steak is actually not as high in fat as you may think, particularly if you choose one of these lean cuts, which have 5 grams of fat and less than 2 grams of saturated fat per 3-ounce serving, on average. What's more, lean beef is an excellent source of protein, iron, and zinc, all important nutrients for active women. One 3-ounce portion of lean beef packs a whopping 25 grams of muscle-building protein, three times the iron (which is important for carrying the oxygen in your blood to your brain and muscles) of 1 cup of spinach, and a third of your daily zinc needs to help support your immune system. Lean cuts of pork, like pork tenderloin, can also be a good source of fat when eaten in moderation. Cured and processed pork, like bacon, often contains loads of sodium and other preservatives like nitrates (which have been linked to increased heart disease and cancer risk), so they're not the healthiest way to consume the other white meat.
Good question. Native hunter and gatherer societies have thrived on diets with a wide range of fat intake. Most experts suggest approximately 30% of calories as a dietary goal for good fats, which should come from a good mix of naturally occurring saturated, polyunsaturated and monounsaturated fats. The Atkins Nutritional Approach recommends higher levels of good fats during the first three weight-loss phases when carb consumption is lower. This higher recommended level of good fats is an integral component of the Atkins plan as it aids in weight loss and energy levels. The Lifetime Maintenance Phase recommends 30%-40% of calories coming from fat – however, the percentage will ultimately depend on your individual level of carb consumption.
That being said, not all dark chocolate is stellar for your health. I recommend choosing a chocolate that contains at least 70 percent cacao or higher. This minimizes the amount of sugar and means you’ll be getting a solid antioxidant boost. And wherever possible, look for brands that do fair trade and use organic cacao beans to get the most bang for your buck.
One way to combat inflammation is to eat more Omega 3s to help balance the ratio. But you can also look at your intake of omega 6s and try to cut back on those as well. Beef that is fed corn or grains is high in omega 6s (conversely grass-fed beef is high in omega 3s.) Safflower, sunflower corn, and cottonseed oils are all high in omega 6s. (Read labels for chips, crackers, cookies, and other processed foods, which often contain these oils.) Soybeans and corn are also high in omega 6s. Cutting back on processed foods and eating more cold water, high-fat fish can help get this ratio back in balance.
Omega-3 fatty acids may help prevent and even treat heart disease and stroke. In addition to reducing blood pressure, raising HDL, and lowering triglycerides, polyunsaturated fats may help prevent lethal heart rhythms from arising. Evidence also suggests they may help reduce the need for corticosteroid medications in people with rheumatoid arthritis. Studies linking omega-3s to a wide range of other health improvements, including reducing risk of dementia, are inconclusive, and some of them have major flaws, according to a systematic review of the evidence by the Agency for Healthcare Research and Quality.
Fat gives your food texture, makes it more filling and – oh yeah – it makes food delicious, too. And while the low-fat diet crazes of the 90s might have steered you away from fatty foods, the truth is that healthy fat is a crucial part of your diet. However, it's important to choose the right types of fat. Some of them offer some serious health benefits, while others offer no nutritional value and pose a serious threat to your health.
Red meat provides us with healthy fats, in particular, conjugated linoleic acid, or CLA—the trans fat that actually helps improve heart health and reduce belly fat—and stearic acid, a saturated fat that actually reduces LDL cholesterol. But grass-fed beef is even better than what you’ve traditionally been grabbing. In fact, a study in Nutrition Journal found that grass-fed beef is higher in CLA, stearic acid, and omega-3 fatty acid (because grass contains ALA and corn does not), and lower in unhealthy palmitic acid, than conventionally raised beef. And when it comes to your waistline, grass-fed beef is naturally leaner and has fewer calories than conventional meat.

Salmon might not get as bad of a rap for being high in fat, but its health benefits are worth repeating. By adding this fish fillet into your diet just twice a week, you’ll get the full amount of heart-healthy omega-3 fatty acids recommended by the American Heart Association. Omega-3s reduce the risk of arrhythmia, decrease triglyceride levels, and can actually slightly lower blood pressure. When you’re at the fish counter, make sure to pick up the right kind—while pink salmon is the second best fish for nutrition and health benefits, farmed Atlantic salmon is one of the worst.
Monounsaturated fats are typically liquid at room temperature but solidify if refrigerated. These heart-healthy fats are typically a good source of the antioxidant vitamin E, a nutrient often lacking in American diets. They can be found in olives; avocados; hazelnuts; almonds; Brazil nuts; cashews; sesame seeds; pumpkin seeds; and olive, canola, and peanut oils.
But wait, bile isn’t the only thing added in here, our pancreas also adds pancreatic digestive juices called lipase to the duodenum which helps break down triglycerides into two fatty acids and a monoglyceride. After this step, though, the fat droplets don’t just disappear. Instead the fatty acids and monoglycerides are absorbed in the microvilli (remember these from Digestion, part I?) and reassembled into triglycerides.
We mean the yolks, not shells. If you’re one of the people who still isn’t sure if you should eat the yolk, here’s your answer: yes! While the whites are all protein, leaving the yolk to contain the fat and cholesterol, there’s no need to worry. The fat in yolks is mostly monounsaturated, and a study by University of Connecticut researchers found that the overall fat profile in egg yolks ultimately helps to reduce LDL (“bad” cholesterol). Not only will it improve your cholesterol, eggs are the number-one dietary source of a nutrient called choline. Choline, which is found also in lean meats, seafood, and collard greens, attacks the gene mechanism that triggers your body to store fat around your liver.
Yes, that’s right. One ounce (about 3 fingers' worth) of dark chocolate counts as one serving and contains about 9 grams of fat. About half of its fat content is saturated, but it also contains healthy fats and numerous other healthy nutrients—vitamins A, B, and E, calcium, iron, potassium, magnesium, and flavonoids (plant-based antioxidants). And did you know a 1-ounce portion of dark chocolate also boasts 3 grams of fiber? Practically a vegetable. Aim for a cocoa content of at least 70 percent for the highest levels of flavonoids.

Dr. Michael and Dr. Mary Eades in their book Good Calories, Bad Calories write about the role that saturated fats found in butter and coconut oil play in immune health stating that the “loss of sufficient saturated fatty acids in the white blood cells hampers their ability to recognize and destroy foreign invaders, such as viruses, bacteria, and fungi”.
Saturated fats are found in animal products (meat, poultry skin, high-fat dairy, and eggs) and in vegetable fats that are liquid at room temperature, such as coconut and palm oils. The 2005 Dietary Guidelines recommend limiting saturated fats to 10% or less of your total calories, while the American Heart Association recommends keeping them to just 7% of total calories.

Dr. Michael and Dr. Mary Eades in their book Good Calories, Bad Calories write about the role that saturated fats found in butter and coconut oil play in immune health stating that the “loss of sufficient saturated fatty acids in the white blood cells hampers their ability to recognize and destroy foreign invaders, such as viruses, bacteria, and fungi”.
Adding eggs with the yolk offers a tremendous amount of benefits. “Current research proves that eggs contribute a boatload of nutrition, including riboflavin, folate, and vitamins D and B12 that can lower the risk of heart disease,” shares Warren. Eggs get a bad rep because they contain cholesterol and saturated fat. But research shows that the cholesterol in eggs (and in the diet in general) doesn’t necessarily contribute to cholesterol in the body. Warren also points out that studies highlight the importance of being cognizant of total saturated fat in the diet, regardless of whether it is from an egg yolk or not. One large egg actually only contains 1.6 grams of saturated fat.
Trans fats are unsaturated fats that have been processed and as a result, behave like saturated fats. Eating trans fats increases the levels of ‘bad’ cholesterol and decreases the levels of ‘good’ cholesterol in the body which is a major risk factor for heart disease. It is important to lower the amounts of trans fats you eat to help you stay healthy.
Fat, fat, fat! Would all of our weight loss problems be solved if we just eliminated fat from our diets? Unfortunately, it's not that simple. We actually need fats -- can't live without them, in fact. Fats are an important part of a healthy diet: They provide essential fatty acids, keep our skin soft, deliver fat-soluble vitamins, and are a great source of energizing fuel. But it's easy to get confused about good fats vs. bad fats, how much fat we should eat, how to avoid artery-clogging trans fats, and the role omega-3 fatty acids play in heart health.
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