Are you afraid of fat? Don’t be. In addition to making food taste good, fat plays an important role in a healthy, balanced diet. Here we cover the basics about fat and how it affects health goals.
At nine calories per gram, fat is the most calorie-dense of the macronutrients (carbs and protein each have 4 grams). This makes sense, since one of the biggest roles of fat is energy storage. Dietary fat is digested into small chains of fatty acids. These chains are picked up by the intestinal cells, reassembled and packaged into vessels called chylomicrons, which are sent to muscle or fat tissue. Once the chylomicrons arrive, fatty acids are again released to be taken up by muscle and fat cells. If you need energy right away — say you take a walk after dinner — they’ll be used to meet those demands. If you go right to bed, they’ll be stored in fat tissue until they’re needed.
Not surprisingly, significant fat breakdown occurs when your body runs on a calorie deficit. In a healthy adult, calorie deficits occur mainly by restricting calories consumed or by undergoing a tough workout. When this happens, your body taps into its own fat stores, breaking them down for energy through a process called “beta oxidation.” This process requires glucose, which can come from carbohydrates or protein, and is most efficient when you’re mildly restricting calories.
The body burns fat during calorie deficits and it also burns fat during normal day-to-day activities. Fat is the primary source of fuel when you engage in low-intensity movements — from sitting in front of the computer to walking the dog. The body does this so it can spare glucose (the good stuff!) for your brain and red blood cells.
Fat is crucial for life. So much so that our bodies figured out a way to make fat even if we eat almost no fat at all. Excess carbs and protein can both be converted into fat and stored as energy. Fat also helps our bodies function correctly in several ways:
FAT MAINTAINS HEALTHY CELLS, ORGANS AND BRAINS
A healthy amount of fat is protective. Fat is an important component of every cell’s membrane or “wall” that shields against invaders. It also protects the organs by cushioning them from the impact of everyday living. Certain fats are required to build and maintain a healthy brain, which is composed of about 60% fat.
FAT FUELS MOST ACTIVITIES
For day-to-day activities — from sitting in front of your computer to walking the dog — fat is the main fuel the body burns for energy. Generally, during activity where the heart rate is less than 70% of its maximal rate, fat serves as the body’s primary source of fuel.
Not surprisingly, significant fat breakdown occurs when the body runs on a calorie deficit. When taking in fewer calories than burned, the body taps into its fat stores, breaking them down for energy through a process called “beta oxidation.” This process requires glucose and is most efficient when mildly restricting calories.
FAT HELPS THE FEELING OF FULLNESS AND MAINTAINS STEADY BLOOD SUGAR LEVEL
Fat aids the release of CCK (cholecystokinin), a peptide hormone that helps you feel full after a meal. Pairing high-fat foods with high-carb foods helps prevent a rapid spike in blood sugar because fat slows digestion and the rate at which sugars from carbs enter the bloodstream.
Fat is found in a wide variety of foods — either naturally occurring or added fat during processing and cooking. Naturally occurring fats tend to be found in dairy, meat and fish, nuts and seeds, oil and fatty fruits (think olive oil and avocado). Added fats tend to be found in processed and packaged goods. Not all fats are created equal when it comes to health. Here is a brief run-down of the common fats found in food:
SATURATED FAT
Solid at room temperature, saturated fat mostly comes from animal sources like meat, particularly red meat, and dairy. Certain plants and their oils are high in saturated fat, such as coconut and palm. Virtually all major health organizations advise us to eat less saturated fat since it raises LDL cholesterol, a risk factor for heart disease. This is why the MyFitnessPal app sets the saturated fat limit at less than 10% of total calories.
TRANS FAT
Most trans fats found in food are synthetically made by taking liquid unsaturated fat and blasting it with hydrogen so it resembles solid saturated fat. This makes foods more shelf stable, easier to cook with, and allows manufacturers to replace saturated fat in their products. However, evidence has revealed trans fats are one of the worst things for the heart. Not only do trans fat increase LDL (bad) cholesterol, but they also decrease HDL (good) cholesterol. For these reasons, the MyFitnessPal app sets the trans fat goal at 0 grams per day.
MONOUNSATURATED (MUFA) AND POLYUNSATURATED FAT (PUFA)
These fats are what we think of when we say “healthy” fats because they don’t carry the same risk for heart disease as saturated and trans fat. Generally, MUFA and PUFA are found in high-fat, plant-based foods such as avocado, nuts, seeds, olives and fatty fish such as salmon, tuna and mackerel.
OMEGA-3 AND OMEGA-6
While they’re technically polyunsaturated fats, the omegas deserve a separate category since the body cannot produce them and must be obtained from food.. Both omega-6 and omega-3 fats play important roles in regulating the immune system. Omega-3 fat plays an essential role in developing vision and the nervous systems. Adequate intake for adults ranges from 12–17 grams per day for omega-6 fats, and 1.1–1.6 grams per day for omega-3 fats. We easily reach the omega-6 fat goal from food because soybean, safflower and corn oil are abundant in the food supply. Omega-3 fats are harder to come by since they are mostly found in fatty fish. This is partly why it is advised to eat more seafood by the Dietary Guidelines for Americans.
The Institute of Medicine (IOM) suggests that fat makes up 20–35% of total calories, but you can eat more or less depending on your goals. The MyFitnessPal app automatically allots 30% of calories to fat, which can be tailored to meet your needs.
To determine fat needs in grams:
Does this match your fat goal in the app? Adjust it if needed.
EAT A MODERATE AMOUNT OF MEAT AND DAIRY
Meat and dairy have a role in any balanced diet, but they shouldn’t make up the majority of your intake since they have saturated fat. Enjoy them in moderation along with plenty of whole grains, vegetables and fruit.
PAIR WITH NUTRIENT-DENSE FOODS
Eating fats along with foods rich in fat-soluble vitamins and minerals allows the body to better absorb them. A good example: use high-fat salad dressing to maximize your absorption of the vitamins and minerals from the vegetables in your salad.
CHOOSE FOODS HIGH IN OMEGA-3 FATS
Most of the fat in our diets supplies us with plenty of omega-6 fats, but we should be getting a better balance between omega-6 and omega-3. Both fats play a role in keeping inflammation in check, so it’s important we get a good ratio of the two.
VARY YOUR COOKING OIL
Different cooking oils provide varying amounts of saturated fat, MUFA and PUFA, plus they impart different flavors and aroma to your food. To get the maximum benefit in a budget-savvy way, purchase olive oil (for low-heat cooking) and canola oil (for high-heat cooking). Olive oil provides valuable MUFA and omega-6 fats, but canola also has a decent amount of omega-3 fats.
EAT FOODS RICH IN HEALTHY FATS
Focus your diet on monounsaturated and polyunsaturated fats such as those listed below:
The nutrition field has recovered from its fat-phobia of the ‘90s. Just in case any of those old beliefs are lurking in your mind, we want to be extremely clear.
Your body stores fat mainly from excess calories. If a calorie excess is available, even if those calories are from carbs or protein, your body is fully capable of turning them into fat for storage.
The body burns a combination of carbs, fat and protein. Fat is the fuel of choice at rest and during low-intensity exercise (e.g. exercising at less than 70% maximal heart rate). The body’s fuel of choice shifts to carbs when exercising harder — at a moderately intense pace and beyond.
Contrary to what the label might say, low-fat and nonfat versions of foods tend to contain more fillers and additives to make up for missing flavor. A common additive is, unsurprisingly, sugar.
In conclusion: