A Simple Argument For Eating Less Fat (Instead Of Less Carbs) To Lose Weight

First off, let me preface, the intention of this piece is to provide the average person who struggles with maintaining or losing body fat with my opinion on a good place to start. I want to begin with the basic understanding of weight loss, caloric balance, and macronutrients. Everything I quickly explain is certainly more complex than described here and will be intentionally over-simplified for the sake of brevity and comprehension.

Fat is essential for the human body. That includes dietary fat, which is the fat we eat, as well as the fat that is stored in our body when we eat too much food and don’t move enough. These two “types” of fat are often used interchangeably (for the sake of readability and to avoid redundancy, I’ll be using both interchangeably as well) but it’s important to understand the difference between them to avoid confusion.

Among other things, dietary fat provides us with essential fatty acids, regulates hormones and absorbs certain vitamins. Without getting into any of the boring science, you can bet that we need it. Unfortunately, with the media sensationalizing every observational study that comes out about how fat is supposedly the magic ticket to eternal life, the general consensus these days is that more fat equals more good. People are adding extra olive oil to their salads, eating more eggs at breakfast, and smothering their toast with butter. According to Statistics Canada, our avocado imports have increased over 255% since 2006, which is shortly after we Millennials offered our greatest contribution to society thus far – the Avocado Toast. This seems to be consistent with our track record as humans to maintain the attitude that “more is always better”. We take anything that is deemed as “good” by the majority and, without second thought, begin to find 49,000 different ways to impose it on our daily lives.

avocado on toast

Now, you’re probably heard the terms “healthy fats” thrown around incessantly for the last few years and you may be wondering what exactly is a “healthy fat”? Things like nuts, olive oil, avocados, and fish are all considered to be healthy sources of fat. They’ve been reliably shown to benefit cardiovascular health and we’re fairly certain it’s because of their omega-3 content and the monounsaturated and polyunsaturated fats in them.

The current guidelines from Health Canada recommend 2-3 tbsp of these fats per day, which is probably low for a lot of people. The recommendations are somewhat reasonable but unfortunately, they still perpetuate fear around the consumption of fat. While I am making an argument here for reducing fat when trying to lose weight, I am not trying to make people afraid of fat.

So now that we have a rudimentary understanding of what fat is, it’s also important that we understand the basics of losing weight. There is much more to this but for the sake of brevity and simplicity I’m going to put it like this: If you consume more food than you require to maintain your body’s current functions, you will gain weight. To the contrary, if you consume less food than you require to maintain your body’s current functions, you will lose weight. (In both cases, weight is a general umbrella for body fat, fluid retention, connective tissue, muscle, etc). When you eat more calories, we call it a caloric surplus. When you eat less calories, we call it a caloric deficit. Obviously, to achieve weight loss we need to eat less calories and put our bodies in a caloric deficit. There are many ways to achieve a caloric deficit, but simply put, the foundation of such is purely a numbers game. (This statement is frustratingly very often strawman’d, so I will go ahead and state very clearly right now that this is not ALL there is to achieving weight loss – I admit it is much more nuanced than this and I promise I touch on the nuances if you keep reading).

So if we need to eat less calories to lose weight, what are calories and how do we eat less of them? Well, calories are a unit of measurement that we use to indicate the amount of energy in food. (If you want the nerdy explanation just google “What Is A Calorie” and you’ll be entertained). Our food is made up of 3 main constituents: protein, carbohydrates, and dietary fat.Each of these macronutrients contain a certain amount of calories (i.e., energy) per gram. (Sometimes fibre and/or alcohol is considered as the 4th or 5th macronutrient)

  • Protein has 4 calories per gram.
  • Carbohydrates have 4 calories per gram.
  • Fat has 9 calories per gram.

I hope you noticed that one of these is not like the others. So with that understood, let’s do some mathing.

  • 100 grams of protein x 4 cals = 400 cals
  • 100 grams of carbs x 4 cals = 400 cals
  • 100 grams of fat x 9 = 900 cals

As you can see, fat contains OVER twice the amount of calories (i.e., energy) as protein and carbs. This is where the basis of my argument for reducing fat when dieting comes from. Just from a mathematics perspective, it makes sense to at least start by reducing fat when dieting.

Let’s see what 100 grams of each macro roughly looks like.

  • 100 grams of protein = 4-5 scoops of protein powder or 4-5 chicken breasts.
  • 100 grams of carbs = approximately 2 cups of cooked rice or 4 medium sized apples.
  • 100 grams of fat = 7 tbsp of olive oil or 8 tbsp of coconut oil.

Look at all the food sources above and guess which ones would fill you up more effectively. What can you eat more of until you feel physically full? Multiple chicken breasts or 7 tbsp of olive oil? Four medium apples or 8 tbsp of coconut oil? Multiple chicken breasts and several apples would surely take up more physical real estate in your stomach than most high fat sources and I think this should be taken advantage of when going through a diet phase.

I think this is also the reason why many people erroneously condemn carbohydrates as the sole reason for their lack of caloric control. Consider pies, tarts, donuts, and cookies – many folks would categorize them as “carb sources” and “it’s the sugar that’s the problem”. When in reality, about half of the calories or more come from the fat content! So why don’t people recognize that? Why do they unfairly blame the carbs in the desserts instead of recognizing the fat content as well? I think it’s due to the fact that fat can hide in the oils and shortenings that take up very little physical space. You can’t SEE fat. Dietary fat is the sneaky macro!


This leads me into some further nuances to the argument…

  1. As previously described, carbs from fibre and starch sources are generally more filling and thus more satiating – resulting in the feeling of fullness on less calories. (Try eating as many baked potatoes or even plain bagels as you can. It would be a fraction of the calories compared to eating as much bacon, peanut butter, or a full fat dressing as you can.) The caveat here is that simple sugars are similar to dietary fat in this context because they’re very easy to overeat due to their low volume makeup, and therefore, reducing these types of carbohydrates may be a good strategy during a diet phase.
  2. Dietary fat is metabolically expensive to break down and use as energy compared to carbohydrates, which your body breaks down into glucose very efficiently. Glucose, being an economically advantageous source of fuel, can provide quick energy in the circumstance where you would otherwise feel lethargic from caloric restriction. This also makes carbs a good choice for anyone who is dieting while also performing resistance training, since intense bouts of lifting weights requires fast and efficient sources of energy to optimize performance.
  3. Finally, carbohydrates generally cost less, making the choice to prioritize the reduction of dietary fat while losing weight a potential consideration for the financially-conscious dieter.
  4. I’ve been focusing on the management of dietary fat so I haven’t really touched on the role of protein, but I’ll make my general heuristic as clear and concise as possible. You’re probably not eating enough. A high protein diet has reliably shown to be safe as well as absolutely essential for overall health. It’s also very helpful during a dieting phase due to it’s satiating effects, as well as slowing the rate of muscle loss during dieting. Protein is the foundation of a good diet and, in most cases, can stay relatively constant whether losing weight or not – it’s the fat and carbohydrates that are adjusted based on current goals. (See the research and reviews from Eric Helms, Brad Schoenfeld, and Stuart Phillips for more on all things protein.)

Losing weight (and body fat) ultimately comes down to caloric balance and whether or not you are consuming less total calories – the amounts of each macronutrient are irrelevant in this context. So whether the diet contains mostly carbs or mostly fats, it doesn’t really matter. What does matter is that your nutrition is structured in a way that is sustainable for the rest of your life. Total calories dictate whether you lose weight, maintain weight, or gain weight. The right macronutrient ratio for someone to lose weight should always be assessed on a personal basis and ideally under the supervision of someone qualified. Things to consider will be personal preference, dietary adherence, training situation, general lifestyle, and health status. For some people, higher fat will fit the bill. For others, it’s higher carbs. My argument for monitoring fats while keeping protein and carbs moderate to high is not for those in the former group who have found themselves successful at sustainable weight loss. From my experience in helping clients take control of their nutrition, most of them are very surprised to discover how much fat they eat when they begin tracking their food.

Finally, all the points I used to support my argument are not hard-and-fast rules. There are surely many folks who are outliers for whom some of my statements may not apply. Also, this opinion is not meant to be taken as a zealoutrous endorsement of carbohydrates, nor a blind demonization of dietary fat. It’s simply meant to offer a practical framework for which someone who wants to begin controlling their caloric intake can start from. So for anyone who has struggled to lose weight and keep it off, I think that monitoring dietary fat consumption is a good place to start.

If you have any questions on food and nutrition or need some further clarification on this post then you can email me at tim@motusstrength.ca!


Photo credit:

Wes Hicks, @sickhews (Featured Image, Colourful Donuts)

Anna Pelzer, @annapelzer (Image 2, Avocado Toast)

Carles Rabada ,@carlesrgm (Image 3, Cheeseburger)

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