Dietary Fat: The Much Maligned and Misunderstood Macronutrient
Welcome to “Diet Basics”, a series where we take all that tasty dietary information and break it down into what you need to know to make better diet decisions in your everyday eating habits. Diet isn’t about a temporary fix or a set of steps you take in the short term to fix everything just so you can go back to bad habits when you’re “done” with the diet. A good diet is a lifestyle choice that you should be consciously making until it becomes habit. This series will arm you with the information you need to make those healthy decisions, and start replacing your bad eating habits (Kit-Kats are not a food group!) with good eating habits (have some carrots, seriously).
Have you heard of protein? Thought so! Have a look at our article about Protein too!
Today we’re going to discuss the most vilified macro-nutrient of the last 30 years: Fat!
What is Fat?
Like protein, we can look at fat from a chemical standpoint and from a nutritional standpoint.
Chemically, what we think of as Fats are what are known as “triglycerides” or, the combination of a glycerol molecule and three fatty acid molecules. Think of the capital letter “E”, where the arms of the “E” are all fatty acids, and the backbone that connects them is a glycerol. Where the arms meet the backbone are called “ester” bonds, which is where a hydroxyl group (HO-) on the glycerol connects to a carboxyl group (-COOH) on the fatty acid. Since each glycerol has three hydroxyl groups, you can connect three fatty acids to each one. Now, you’ve got a triglyeride! I know, I know. Your excitement is palpable. Calm down; it’ll be okay.
Makes perfect sense, right? No? Crap. Ok, have a picture!
The parts of a triglyceride before they are connected.
Pictures and a thousand words and all that. Take three of those Big Ol’ Fatty Acids, connect them to one of the Hydroxl groups each, and you’ve got it.
“But wait,” I hear you cry. “I don’t care about the science. I’m not that nerdy! Why do I care about this molecule?!”
Ok, ok! Lets talk turkey…er…fat. Dietary fat comes in three types that you need to care about, and that should be called out on your food labels: saturated, unsaturated, and trans fats. Now, these are terms that get thrown around all the time but I’ve found that not everyone knows what they really mean or why we should care. Lets fix that!
First, you need to understand that within that fatty acid example I showed you above, there is a “hydrocarbon chain” which is really just a series of Hydrogen and Carbon atoms that are connected to each other. The important part here is that in that chain you can have carbon-hydrogen bonds and carbon-carbon bonds. The type of fat you have, depends on whether or not the three fatty acids in your triglyceride contain the maximum number of Carbon to Hydrogen bonds that they can possibly have. Here’s how they break down:
Saturated Fats have three fatty acids that all contain the maximum number of Carbon to Hydrogen bonds that it is possible for them to have. So, between all three fatty acids, there is not a single Carbon to Carbon bond. The fatty acids can have different numbers of Carbon atoms (usually between 13 and 17 carbons) but they are all connected to as many Hydrogens as possible.
Unsaturated Fats have at least one Carbon-Carbon bond in at least one fatty acid out of the three that make up the Fat. In this category you will also see Monounsaturated Fats, where there is only one Carbon-Carbon bond, and Polyunsaturated Fats where there is more than one Carbon-Carbon bond. Basically, at least one Carbon atom is not fully “saturated” with as many Hydrogen atoms as it could otherwise handle.
Trans Fats are actually Unsaturated Fats which are organized differently than the typical Unsaturated Fats. I won’t go into a lot of detail here, since it gets even more science-y than we have already, but suffice to say the a Trans Fat has the Carbon-Carbon bond in a place that causes them to not break down as easily. Their full name is “trans-isomer unsaturated fats”, but they will commonly be refereed to as “trans fats” or “trans unsaturated fats” on food labels.
So why do you care? What’s the difference?
First, energy content. A Saturated Fat with 13 Carbon atoms, for instance, will have more Carbon-Hydrogen bonds than an Unsaturated Fat with the same number of Carbon atoms. Since the energy from fats is actually produced as Carbon-Hydrogen bonds are broken during digestion, the more of these bonds you have, the more energy the fat will provide.
Second, how “stackable” or dense they are, which equates to how easily they solidify at different temperatures. Saturated Fats can stack easily and thus are normally solid at room temperature (like tallow or lard) while Unsaturated Fats don’t stack as easily and tend to be liquids at room temperature (like linseed or olive oil).
What about trans fats? These kind of suck, honestly. They combine the stackability of Saturated Fats, with the stronger bonds (Carbon-Carbon) of Unsaturated Fats. This means they solidify very easily but they don’t break down when they go through the human metabolic system. These characteristics can lead to significant increases in the risk of coronary artery disease, as trans fats build up on your arterial walls.
What does Fat do?
Fat plays some very specific roles in your delicate, squishy human system:
- Some vitamins are only fat soluable, meaning they will only be absorbed and used when there are fat molecules involved in the process. These include Vitamins A, D, E, and K.
- Fat maintains the health of hair and skin, insulates organs again shock (i.e. moving violently), maintaining body temperature, and helping cells function correctly.
- Fat is the highest calorie macro-nutrient that you can take in, and the body loves to use it as an energy source (as long as you aren’t overeating carbs, which we’ll talk about next time). Fats have 9 calories / gram of energy content, and you get that from the glycerol portion of the fat molecule as it’s broken down in the liver.
- Fat helps fight disease! Seriously, it’s awesome. When something nefarious enters the body, the nasty little invaders can be stored in new fat tissue until the immune system has the chance to metabolize of remove it. Eventually, the junk stored in the fat tissue can be excreted via urination, defecation, blood-letting (accidental or otherwise), sebum (which is what makes your skin feel oily), and even hair growth.Take that in for a second: fat helps you fight disease by putting it into your hair and kicking it out of the body. That’s…kind of crazy-awesome.
- Some fats, like proteins, are essential nutrients, meaning they cannot be produced in the body. Don’t eat fats regularly, and you start a deficit in these essentials, and bad things happen to your overall health.
- Fats are useful in the production of certain hormones, like leptin (hunger response) and testosterone (all things manly, including body fat maintenance), which are essential for good health.
Fat tissue in the body, also called Adipose Tissue, is long term storage for energy. Your body loves to use the stored fat as energy by breaking it down into fatty acids and glycerol, as long as you aren’t overeating cards (which most of you probably are, it’s a thing). Adipose tissue is good, because it provides all those benefits we’ve talked about above, but it can become a problem when your diet doesn’t regulate how much adipose tissue you keep on your at one time. This is called “body fat %” and regulating it is one of the main goals of proper diet and exercise.
Where can I get Fat?
First, you also need to know one or two more things about dietary fat…
- Myth: all fat is bad
- Fact: Saturated Fats and Trans Fats tend to cause higher bad cholesterol (LDL) rates and seem to be related to higher risk of heart disease.
- Fact: Unsaturated Fats (mono- and poly-) actually act in the reverse, decreasing bad cholesterol (LDL) by raising good cholesterol (HDL), and decreasing risk of heart disease. There is also evidence that they support good hormone production, lower blood pressure, prevent irregular heart beat, and have beneficial effects on blood sugar and insulin levels.
So it stands to reason that you should eat your fats from more unsaturated sources and avoid saturated/trans fat sources. That being said, here’s some good stuff to eat:
- Olive oil
- Canola oil
- Sunflower oil
- Peanut oil
- Sesame oil
- Nuts (almonds, peanuts, macadamia nuts, hazelnuts, pecans, cashews)
- Peanut butter
- Soybean oil
- Corn oil
- Safflower oil
- Sunflower, sesame, and pumpkin seeds
- Fatty fish (salmon, tuna, mackerel, herring, trout, sardines)
And here’s some stuff high in the fats we’re trying to avoid:
- High-fat cuts of meat (beef, lamb, pork)
- Chicken with the skin
- Whole-fat dairy products (milk and cream)
- Ice cream
- Palm and coconut oil
- Commercially-baked pastries, cookies, doughnuts, muffins, cakes, pizza dough
- Packaged snack foods (crackers, microwave popcorn, chips)
- Stick margarine
- Vegetable shortening
- Fried foods (French fries, fried chicken, chicken nuggets, breaded fish)
- Candy bars
Now, you don’t need to avoid the bad fats completely, but you should limit your intake of the bad fats, and get most of your calories from the good fats. Try to take in 20g or less of Saturated Fats per day, and 5g or less of Trans Fats per day.
How much Fat do you need per day?
So, our dietary Fat needs are actually based on our Protein and Carbohydrate intake. For that reason, we’re going to borrow some content from the last article (Protein) and the next article (Carbohydrates). Here’s the math:
1. Protein and Carbohydrate intake per day:
- Workout Day: 100g ; 400 cal
- Resting Day: 50g ; 200 cal
- My stats: 167 lbs / 14.5% body fat / 142.8 lbs Lean Mass
- Protein Goals:
- Workout Day: 0.8 g / day / Lean Pound = 114.24 g ; 457 cal (rounded)
- Resting Day: 0.7 g / day / Lean Pound = 99.96 g ; 400 cal (rounded)
2. Next, we need to know how many calories we need each day to account for all the stuff our body does (breathing, walking, etc). We’re going to use our Lean Mass to find our Basal Metabolic Rate (fancy term for “calories per day”).
- Here are the BMR formulas for weights in pounds as well as weights in kilograms:
- BMR = 370 + (9.82 x Lean Mass) [if using weight in pounds]
- BMR = 370 + (21.6 x Lean Mass) [if using weight in kilograms]
- Using the BMR in Pounds formula (I’m from the U.S., you’ll live)…
- 370 + (9.82 x 142.79 lbs) = 1772 calories per day
- Note: I round my numbers so you don’t have crazy figures with 10 decimal places. I always round calories per day down.
- On workout days, I add 10% to this number and on non-workout days I use the base number alone.
- Work Day BMR: = 1772 * 1.10 = 1949 calories per day
- Rest Day BMR = 1772 * 1.00 = 1772 calories per day
3. Lastly, based on BMR, calories from Protein, and calories from Carbohydrates, we can find Calories from Fat. Fat has 9 calories per gram, in case you didn’t know.
- Workout Day:
- BMR: 1,949 cal
- Protein: 457 cal (114g)
- Carbs: 400 cal (100g)
- Remaining: 1,092 cal
- Fat: 1,092 cal / 9 = 121g
- Resting Day:
- BMR: 1,772 cal
- Protein: 400 (100g)
- Carbs: 200 (50g)
- Remaining: 1,172 cal
- Fat: 1,172 / 9 = 130.2g
Now we have all the numbers that are fit to…er…”num”?
Anyway! On workout days I’ll take in 121g of Fat, accounting for about 55.8% of my total calories that day. On resting days I’ll take in 130g of Fat, accounting for about 66% of my calories for that day. I know this seems high, and the first time I figure it out I thought so too. The truth is, we’ve all been told over the last 30 years that “Low Fat Diets” are the key to long life, curing the obesity epidemic, and wiping out Type-2 Diabetes. But what’s been happening since the 1980′s? The exact opposite! Ever since we, as a society, stated vilifying Fats and sanctifying Carbs (which, trust me, are nice and loaded into those low-fat foods), we’ve been getting fatter, with weaker hearts, and we look like shit!
Don’t believe me? Ok, why don’t we see what those smarty-pants’ over at the Harvard School of Public Health have to say about it:
According to a press release in Feb 2011 titled Obesity has doubled since 1980, major global analysis of risk factors reveals, they have found the following “fun” facts:
- From 1980 to 2008 (28 years), the world-side prevalence of obesity has almost doubled, so that now almost 1 in 10 adults are obese.
- In 1980, 4.8% of men and 7.9% of women were considered obese (BMI over 30). In 2008, this has risen to 9.8% of men and 13.8% of women.
- The USA has the highest average BMI in the world among wealthy nations.
And according to the Center for Disease Control in the USA, more than one third (35.7%) of the adult population of the USA was obese from 2009-2010.
So, what this illustrates is that the popular opinions about diet, to date, have been pretty friggin’ wrong and misguided. The more low-fat junk that went on the market, the fatter we seemed to get as a world and especially as a country in the USA. So if low fat isn’t the answer everyone said it was, that means that fat is a perfectly reasonable part of a good diet.
Now, go have some peanuts, and tune in next time for some delicious information regarding Carbohydrates: The New Menace.