Low Carb/Keto Dieters! Are You Sabotaging Yourself by Not Tracking Your Macros?

Low carb food

If you’ve never tracked your macros, you’re not alone.

If you don’t even know what a macro is, you’re probably even less alone.

But learning about macros – what they are, how they work, how they can help your diet – could be the single most effective thing you could do to encourage steady weight loss and avoid plateaus.

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Macros: What they are and how they work

Every food is made up of 3 macronutrients: fat, carbohydrates, and protein. These three nutrients are what we refer to as “macros.” All of your calories come from these specific macronutrients.

“I think counting macros can be hugely useful – perhaps the most useful thing – for people wanting to reach their health, fitness or weight loss goals.” – Harry Smith, Personal Trainer

To better understand the relationship between calories and nutrients, it’s important to know how many calories come from each gram of each macro.

  • Fat: 9 calories per gram
  • Carbohydrates: 4 calories per gram
  • Protein: 4 calories per gram

This is why fat-heavy foods tend to be so calorically dense. Even though you eat a small amount of cheese, it’s higher in calories because it’s mostly fat, and fat yields more calories per gram than either carbs or protein.

Check out the following label from Kraft Velveeta Cheesy Skillet Singles:

Nutrition Label
(Image from Polka Dots on Parade)

Now, notice the amount of fat, carbs, and protein that make up one serving of macaroni and cheese:

  • Fat – 10 grams
  • Carbohydrates – 30 grams
  • Protein – 20 grams

If we do a little multiplication and some addition, we can see exactly where the 290 calories come from:

Fat = 9 calories per gram x 10 grams = 90 calories
Carbohydrates = 4 calories per gram x 30 grams = 120 calories
Protein = 4 calories per gram x 20 grams = 80 grams

90 fat calories + 120 carb calories + 80 protein calories = 290 calories.

Easy math!

What the macros actually do

So what exactly are those macros, and how do they work in your body?

Low carb meal


Carbohydrates are very misunderstood – almost as much as fats, which you’ll read about in a second. Many times, I’ve heard people say “but you have to have carbs to live!” then turn around and shove a large order of McDonald’s fries (or something similar) down their throat. It’s simply not true. Technically, you don’t have to have carbs to live. Besides, if you’re following a well-balanced low carb or ketogenic diet, you are eating carbs; you’re just eating them in the form of vegetables and nuts – in other words, healthy sources.

Carbs are stored in our brain and body as glycogen, and our bodies use the carbs for energy when we’re not in ketosis. Common sources of healthy carbs are nuts, vegetables, and berries.

Healthy carbs


Protein is key on a low carb diet, because when you eat sufficient protein, it keeps you feeling fuller longer. This obviously helps us stay satiated and keeps us from overeating. Protein is also important for building muscle, or maintaining it if you’re trying to lose weight.

You can find protein in eggs, meat, fish, and dairy products (although you should keep an eye on the nutrition label for the diary products if you’re low carb or ketogenic).


Fat is possibly the most misunderstood of the macros. For decades, people have been told to eat a low fat diet, lest we run the risk of heart disease. However, studies now show that high fat diets are not the dangerous culprits that we’ve been conditioned to think that they are.

Let’s get something out of the way first – our bodies require fat to live. Healthy fats assist in our brain function and vitamin absorption, and help regulate our hormones. Common places to find healthy fats are in nuts and nut butters, oils, fish, meat, avocados… it’s a long list!

Low carb snack

What to do with what you know now

Knowing how to read a nutrition label simply tells us how much of each macro a particular food has. Knowing how this food fits into your diet comes next.

Depending on the type of diet you’re on, you’ll probably look at nutrition labels differently than others might. For example, someone following a low fat, high carb diet would probably stay away from heavy cream, because it’s too high in fat. However, a person on a ketogenic diet who struggles to get in enough fat would probably love it.

So why does this matter? Well, in order to make sure you’re eating the right balance of foods, you have to know what macros they consist of. Even before that, though, you have to know the guidelines of the diet that you’re following.

There are lots of resources out there that will advise you on setting macro limits for any kind of diet. Googling ‘macro calculator’ will give you all the results you need.

Keto macro calculator
(Image from Ruled.me)

Let’s look at some general guidelines first.

Low Carb Diets:

According to the Mayo Clinic, “a daily limit of 0.7 to 2 ounces (20-60 grams) of carbohydrates is typical with a low-carb diet.” The Atkins 40 diet gives us a limit of 40 net carbs per day. Diabetes.co.uk recognizes a low carb diet as being “under 130g of carbs.”

So how do you know what your target should be?

Obviously, the definition of low carb is very flexible, and the only true answer to “how many carbs should I eat on a low carb diet” is however few your body can handle while still performing efficiently (and not making you miserable!). From the sources we’ve checked out, it’s safe to say that a reasonable range for a low carb diet is between 20 and 150 grams.

The formula that goes into calculating specific macros is very involved and specific to the individual, so I can’t figure that out for you. But having an idea of how many carbs you can eat gives you a good idea of where to start.

If you’re trying to lose weight (and you probably are, or you wouldn’t be here!), I’d suggest spending a day or so eating normally, and tracking everything that you eat honestly. Find out how many carbs you’re eating on a daily basis, and that gives you an idea of how much to decrease your intake.

For example, when I was eating a relatively healthy diet that wasn’t low carb, I was taking in about 200-250 grams of carbs per day. Knowing this, if I chose to reduce my carb intake for weight loss, I could assume that dropping my carb limit to 150 grams per day is a good starting point.

Low carb breakfast
A breakfast of oatmeal wouldn’t work on a ketogenic diet, but a low carb diet is more flexible when it comes to carbs.

Once you’ve decided where to start, maintain that carb limit consistently for about two weeks before making any changes. If the scale isn’t moving enough for you after a couple of weeks, you might consider dropping down to a lower limit. Again, this all depends on how your body responds to a low carb lifestyle.

Ketogenic diets:

A ketogenic diet is much less flexible than a low carb one. The basic tenet of a ketogenic diet is that you have to stay under 20 net carbs per day. This carb limit is key because of the way keto works.

Under normal circumstances, your body burns glucose (carbohydrates) for energy. Once it has used up all of the glucose that it needs for energy, the rest is stored on your body as fat. This is the underlying idea behind low carb diets in general. If you keep the number of carbs fairly low, then you won’t have excess glucose to store as fat on your body, keeping you from gaining weight.

Keto diet carbs

On a ketogenic diet, we switch up our metabolic process. We start by cutting carbs significantly (most experts recommend 20 net carbs or fewer per day). This triggers a reaction in your body. Your body is accustomed to using that glucose for energy, but when it doesn’t, it goes into sort of a panic mode. It starts looking for other sources of fuel, and turns to fat instead. If you’re doing a ketogenic diet, then there isn’t any excess glucose to be stored as fat. If you manage your macros well enough, you won’t keep any excess fat, either, because you’ll only take in what your body needs for energy.

Once your body is accustomed to burning fat instead of glucose, it’s possible that you may be able to take in more carbs and stay in ketosis. (Check out 3 Ways to Measure Ketones to find out how to make sure you’re in ketosis.) I don’t mean it’ll ever be okay for you to eat upwards of 100 carbs a day, but your body may be slightly more flexible with what it’s able to handle.

Having said that, it’s still important to keep yourself under that limit, whatever it ends up being (for simplicity’s sake, I’m going to go with 20). Your body becomes fat adapted – burning fat for fuel – when you’re in ketosis. If you “cheat” on your diet regularly or go over that carb limit, you’re going to be taking your body out of ketosis, and it will revert to burning glucose, rather than fat.

Ketosis is a fantastic way to lose a lot of weight in a short amount of time. Personally, I find that I need a strict diet with very clear parameters; too much choice, and I’ll choose the wrong foods for my body.

If you’re like me, and you can benefit from a clear-cut, no-nonsense diet, consider keto. If you don’t think you’ll be able to stick to it as rigorously, do yourself a favor and start out following a low carb diet that allows more flexibility, and see how that works for you before making drastic changes.

Low carb food

How not tracking macros can sabotage your diet

So now that you know what macros are, how they work in your body, and how to (approximately) figure out your macros, let’s talk about how not tracking can sabotage your diet.

Low carb diets require lower fat percentages than ketogenic diets. Low carb isn’t necessarily the same as low carb, high fat (keto). It’s easy to find LCHF tags all over the internet with recipes and new ideas, but you have to be careful if you’re following these recipes (and basically using these macros) while not in ketosis.

As I mentioned before, when you’re in ketosis, your metabolic processes are different. Your body begins to burn fat instead of glucose. Basically, since your body is more effective at burning fat, it’s okay to have a higher fat intake on keto. However, if you’re simply low carb, then the only fat you’re burning is through exercise (aside from normal body processes). Therefore, a significantly higher fat intake means that fat is going to be stored on your body.

Because of this it’s important that if you follow a low carb diet, you balance your macros so that you’re not replacing too many of the carbs with fat.

Ketogenic diets require a pretty specific set of macros. It’s much harder to give specific macros for low carb diets, because that covers such a large range of intake amounts. As I mentioned before in this article, the number of carbs allowed on a low carb diet can be anywhere from 20 to 150, but a ketogenic diet requires a limited number of carbs – usually 20 or fewer net carbs.

If you’re just starting keto, you’re probably safe tracking just carbs at first. Most people will see a significant change simply by limiting their carbs; for the majority of us, it’s a huge difference! However, once you’re accustomed to which foods you can safely eat, it’s a good idea to evaluate the rest of what you’re eating.

Keto is a high fat, moderate protein, low carb diet. A good starting point is to get 5% of your calories from carbs, 65% from fat, and 30% from protein.

Keto macros

The great thing about keto is that this is where you can be flexible; if you don’t find that you feel full after meals, try increasing your fat percentage and lowering your protein percentage.

If your weight is stalling, it’s worthwhile to consider checking your protein levels. A good target is to eat 1 gram of protein per kilogram of body weight. For example, about 60 grams of protein if you weigh 60 kilograms (132 lbs.), or 90 grams of protein if you weigh 90 kilograms (about 198 lbs).

If you’re not sure where to start, jump in with 5% carbohydrates, 65% fat, and 30% protein. Monitor and adjust from there.

Low Carb and Keto: Not One-Size-Fits-All

I try to do my best to provide readers with general guidelines for both low carb and ketogenic diets. Still, it’s important to remember that neither diet is one-size-fits-all. What works for your BFF may not work for you at all. It’s of utmost importance that you listen to your body, and do what’s right for you!

Take the guesswork out of your Keto or Low Carb diet!

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