Fat can make you fat, if you intake enough calories from fat and store that as excess energy in fat cells. However, fat isn’t what makes a person fat in general. Properties of fat aside, weight loss and weight gain are purely based on calories in and stored vs. calories out.
Does Fat Make You Fat?
Fat can make you fat, but it isn’t the only thing that causes weight gain. Fat is high in calories and is easy to store as fat cells, but in general, it is storing more calories than you burn (from fat, carbs, or protein) that causes weight gain. Below we discuss good fats, bad fats, and how fats do and don’t affect weight gain and weight loss.
FACT: Fat, specifically Omega 3 and 6 fatty acids, are essential. Our body doesn’t make them and they must be taken into the body via food (or supplements). This means one should never eliminate fat from their diet. A human can survive without carbs, but not without the essential acids found in fats and protein.The Deal with Fat.
Understanding Fats and Weight Gain
The first thing to understand about fats and weight gain is that all macronutrients (carbohydrates, proteins, and fats), all the parts of food that provide energy, can cause weight gain (as “body fat” is just stored energy from macronutrients). So fat can cause weight gain, just like carbs and proteins can, but it isn’t only fat that causes weight gain. In fact, fats tend to be filling and can help limit weight gain for this reason.When You Burn Fat, Where Does it Go?
FACT: Fat has the highest calories per gram of any macronutrient and is easy to store as fat. Despite this, it is an essential part of any healthy diet (even diets aimed at weight loss). Learn more about losing weight.
How Fats Can Cause Weight Gain
Despite the fact that other calories sources can cause weight gain, fats (especially bad fats) can be problematic for a few general reasons:
- Fats have a higher density of calories per gram. Proteins and carbohydrates both contain 4 calories per gram, while fat provides 9 calories per gram.
- Fats and simple carbs become fat cells easier than protein and complex carbs, as less energy is burned conserving the calories from simple carbs and fats as fat cells. Protein takes the most energy to digest (20-30% of total calories in protein eaten go to digesting it), carbohydrates (5-10%) and then fats (0-3%). With that said, these are estimates, each food is unique, as is each person’s biology and metabolism.
- Unhealthy fats (like the oil on potato chips) have little to no nutrients and a molecular structure that isn’t as useful for our bodies as good fats (like in an avocado or fish). Good fats are almost always found in things that you would think would be healthy in the first place like nuts and seeds. Our bodies need essential (meaning our bodies must get them from food) fatty acids (Omega 3 and 6), and those are found in the largest quantities in healthy fats.
- Unhealthy foods that are low in micronutrients are less filling than the right balance of foods rich in different acids and micronutrients. Unhealthy fats and unhealthy simple carbs (especially sugars and processed foods) tend to lead people to gain weight (from a fully food-based perspective).
FACT: The main culprit in weight gain is simple carbs (including sugars) as they are most likely to suppress feelings of satiation and cause feelings of hunger. Learn about insulin, glucose, and weight gain or see our page on “how to lose weight, according to science,”
TIP: Fiber is a carbohydrate, and as such as four calories per gram, however, our bodies can’t fully digest fiber. Soluble fiber ferments in the GI tract and contributes an effective two calories per gram, insoluble fiber about 0 calories per gram.
FACT: A calorie is a calorie in the sense that all calories are just a measure of energy stored in food. However, our body processes different macronutrients differently, the digestion process burns away some of the calories in food (“the thermal effect of food”), and foods have different micronutrients and acids too. When we consider all of this, we can say a calorie is only “just a calorie” in a general sense, but what you eat does matter in practice (both regarding the amount of energy your body synthesizes per calorie and how much nutrition each calorie brings with it). See A calorie isn’t a calorie By Helen Kollias.
TIP: There is no perfect theory of fat, there is what we know (AKA the facts like the ones on this page) and then there is what we understand based on that. With that said, anyone interested in the nature of fat and dieting should check out The Secret Life of Fat by Sylvia Tara PhD. Sylvia not only describes the nature of fat in detail, she also gives some interesting diet advice (such as suggesting that waiting longer hours in between one’s last meal and first meal is a key to weight loss due to fat burning hormones we release while we sleep). Pair that with our advice about metabolism and small meals and insulin and you are one step closer to a great science-based diet plan.
TIP: People need a balance of macro and micro nutrients. So a balance of all the good proteins, fats, carbs and water is essential, and consideration must be taken to ensure a balance of good fats while avoiding bad fats, processed foods, and refined sugars. It all boils down to do with the molecular structure of the macronutrients and the micronutrients contained in the foods.
What are fats? (technical answer) Fats are triglycerides, as such, they are primarily composed of two things: glycerol (specifically in the form of monoglyceride) which turns into glucose to be used as energy, and three fatty acids (each fat has a wide range of fatty acids, but only two are essential). Most fats (especially natural ones) also have trace amounts of vitamins, minerals, and cholesterol. The three fatty acids attached to a given fat molecule (chains of H, C, and O molecules which our bodies can use or convert to energy) are held in place by a “glycerol backbone.” This is a gel made of sugar that the chains attach to, and our body can convert to energy easily. The geometric chemical structure of the H, C, and O molecules dictates the viscosity of the fat at different temperatures, and the structure determines whether the fat is healthy or unhealthy. All of our body’s energy comes from fatty and amino acids and types of sugars found in carbohydrates, proteins, and fats. All energy is chains of H, C, N, or O going in, which then combines with a “side chain” of vitamins, minerals, and hormones for the metabolizing process. Metabolization is the process of turning food into energy.Fat: Part 1 of 4 “Free Fatty Acids and Triglycerides.” Chemistry, at its core, is physics. So what is fat? A bunch of H, C, and O atoms in certain relationships that our body can use as energy. The N atoms are found in proteins, but that aside proteins work pretty much the same way.
Good Fats Vs. Bad Fats
Monounsaturated and Polyunsaturated are good and are found in natural fruits, grains, and veggies. Saturated fats are OK and are found in animal fats like dairy, fat, and meat. Trans Fats are generally “bad” and are often found in processed food. They should be limited, but not necessarily avoided.
TIP: Almost no fat we eat has only one type of fat in it. Almost all fats are composed of monounsaturated, polyunsaturated, and saturated fats (although many don’t include trans fats). Saturated means the Carbon chains are saturated (filled, or mostly filled) with Hydrogen atoms, Mono means one chain; Poly means a double bond, unsaturated means the Carbon chains aren’t saturated with Hydrogen. Below are foods that have high concentrations of a fat type.
1. Monounsaturated fats are found in high concentrations in:
- Olive, peanut, and canola oils
- Nuts such as almonds, hazelnuts, and pecans
- Seeds such as pumpkin and sesame seeds
2. Polyunsaturated fats are found in high concentrations in:
- Sunflower, corn, soybean, and flaxseed oils
- Flax seeds
- Canola oil – though higher in monounsaturated fat, it’s also a good source of polyunsaturated fat.
Polyunsaturated fats include the Omega fats:
- Essential Omega-3 fats are an important type of polyunsaturated fat. The body can’t make these, so they must come from food.
- Essential Omega-6 fats are found mostly in liquid vegetable oils like soybean oil, corn oil, and safflower oil.
- Non-Essential Omega–9 and Omega-12 fats are non-essential but are found in animal fat, vegetable oil, olives, nuts, and seeds.
3. Saturated fats are found in animal foods. They are fats that are solid at room temperature. They are found in
- Red Meat
- Animal fats
- Milk and Cheese
TIP: Eggs are the exception here, Eggs have saturated, monounsaturated, and polyunsaturated fats.
4. Trans fats can be natural or artificial but are most commonly artificial. They are found in high concentrations in:
- Processed foods.
- Snack foods, such as chips and crackers.
- Some margarine and salad dressings.
- Foods made with shortening and partially hydrogenated oils
Other Factors to Consider About Fats
Each body type is different, exercise is a major factor, and there are mental aspects to weight gain and loss too, so the complexity should be noted alongside the above generalization.
Here are some other considerations regarding weight gain and facts:
- The macronutrients are complex and simple carbohydrates. Protein is contained in meat, veggies, and grains. These contain amino acids. 9 of the amino acids are essential. There is also Fat, which includes saturated, monounsaturated, polyunsaturated, and trans fatty acids. The essential Omega 3 and 6 are simply two of many fatty acids, all but 3 and 6 can be synthesized by the body.
- Only Simple Carbs, Complex Carbs, Protein, fats, and a fourth category Fiber have calories. Fiber describes a carbohydrate that humans can’t fully digest; or in the case of insoluble fiber, can’t that humans can’t digest at all.
- Amino and Fatty acids describe the molecular structure of the protein or fat. Some chains are healthier than others due to their chemical structure, some are essential. Because they include structures our body can’t create on its own, they must be taken in from food.
- Whatever type of acids you take in is the type that gets used to create your body including your fat cells, muscle cells, etc. The details of the metabolic process aside, your body uses the same molecules chains you take in. So it does matter that you eat good fats and not bad ones; if you don’t get your essential fatty acids you can suffer health problems. Bad fats are less useful for your body.
- Macronutrients describe energy, micronutrients (vitamins and minerals, which are also contained in food) describe non-energy nutrients. Other non-energy nutrients include a few other important things like cholesterol. Even though vitamins, minerals, water, cholesterol and other parts of foods aren’t energy, they are still essential for metabolizing the food we eat to turn that food into energy, ADP and ADT conversion).
FACT: Fats aren’t “empty calories,” fatty acids are vital for proper mental function, and general health and trace micronutrients found in fats are also important.
Additional Advice for Diets Concerning Fats
All diets that have you cut out a food group are, in my opinion, incorrect. It’s hard enough to get the right molecules and micronutrients with a balanced diet. Consider taking good quality vitamins and other healthy non-narcotic supplements as needed.
Healthy fats are contained in foods that provide healthy micronutrients. Eating an avocado, which contains mostly good fat, may mean eating more calories per gram than Cotton Candy. However, cotton candy is pure, simple carbs. The avocado will leave you feeling fuller and more satisfied due to its healthy fats and micronutrients. Cotton Candy will spike your blood sugar telling your body to store fat and make you feel hungry as a hormonal response to the sugar.
Despite the drawbacks of fats, healthy fats are an essential part of a balanced diet. Paired with the right micronutrients and macronutrients, they are essential to any weight loss regiment.
We will summarize our position with a video from SciShow featured on our page on “Does Weight Loss Get Harder As Body Fat Gets Lower?”What Happens When You Stop Eating? This is the real answer, as you can see it concurs with our findings.
- DEMOLISHING THE “FAT MAKES YOU FAT” MYTH
- Eating Fat Doesn’t Make You Fat, Study Finds
- A calorie isn’t a calorie
- How to Correctly Count Calories – Foodie Fiasco
- 4. Power: Pathways that make ATP
- types of fats
- Dietary fats: Know which types to choose
- ESSENTIAL FATTY ACIDS – General Discussion