Low-carb diets have gained great popularity the past several years. Even though I’m skeptical about any diet that has the word ”low” in it, many have achieved great results from this way of eating. So it seems like low-carb dieting really works.
That said, hundreds of diets work. The question is, whether it’s superior to other forms of dieting or not. Giving up carbs is not easy for many of us. So if we all decide to go low-carb, then there needs to be an additional benefit.
By using the currently available scientific research on this matter, we will draw an objective conclusion on whether or not low-carb dieting is the most effective way to burn fat.
Insulin, Your Worst Nightmare?
Low-carb diets supposedly work better for fat loss because you are keeping your insulin levels most of the time.
Insulin is a hormone that is released after consuming carbohydrates and protein. Among other things, this hormone is responsible for nutrient partitioning. Meaning, insulin transfers the needed nutrients to tissues (including fat tissue) after food consumption.
Once insulin is released, your body’s ability to burn fat is suppressed and you will most likely store body fat.
Before you start throwing out all of your chicken and rice, you need to understand that your body is not in constant “fat-burning” or “fat-gaining” mode. It constantly switches from gaining fat after you feed it to burning it when it’s needed.
This graph by Weightology showcases this quite well.
To clear all potential confusion regarding this graph, read the simple example below.
You consume 800 calories at 3 PM and it gets absorbed in 4 hours (rough estimate). Your body will gain a part of it as fat because in those 4 hours your energy needs are not 800 calories, but more around 400 calories if you burn 2500 calories per day (2500*24/4=417). During periods of fasting (which can be as small as a couple of hours), your body will start burning fat because at that time there’s no external energy source (food) available.
If throughout the day you burn more fat than you gain, you’ve lost fat (and vice versa, of course). This is simply achieved by maintaining a caloric deficit. This forces your body to burn more fat than it gains OVERTIME.
Low-carb diets minimize insulin spikes
During a low-carb diet, you primarily eat fat. Research shows that high-fat food sources don’t trigger a significant insulin response. Since insulin is seen as the only hormone that triggers fat gain by many, it seems logical to think that you won’t be able to gain much fat if you keep carbs and protein low. After all, lower insulin levels equal less fat gain, right?
First of all, research shows that your body is capable of gaining fat when insulin levels are low. If this wasn’t the case, you could eat unlimited amounts of dietary fat and stay lean. Fat gain due to excess dietary fat occurs through an enzyme known as ”Acylation Stimulating Protein”.
Second of all, fat breakdown also gets suppressed after eating dietary fat, just like when you get an insulin spike. In both cases, this happens due to the suppression of the enzyme ”hormone-sensitive lipase”.
And last but not least, research by the Scottish Agricultural College shows that higher insulin responses do not have to equal more fat gain over time. Fat accumulation is not a response to insulin spikes from carbohydrate consumption, it’s a response to systematically eating at a caloric surplus.
So, for healthy individuals, insulin is not something you should constantly worry about. Spiking insulin by consuming carbs or protein will not make you a “fat-gaining machine.”
Comparing Low-Carb To Its Alternatives
In theory, it doesn’t seem like the theoretical ”fat-reducing” benefits of low-carb diets hold much truth. But what matters most are the eventual results you achieve from low-carb diets. That’s what we’ll be looking into now.
By looking at low-carb research, we see that many studies find low-carb diets to be effective for weight loss. This is quite logical since low-carb diets deplete muscle glycogen (glucose stored in muscles).
This, in turn, will make you a few pounds lighter. It’s safe to say that this kind of weight loss is not what you are shooting for. Actually, weight loss, in general, shouldn’t be your number one concern.
Most of us want to improve body composition (less fat and more muscle). So ”more weight loss” doesn’t equal a better end result, more fat loss and muscle preservation does.
Why not all studies are useful
We know through a large body of evidence that a high protein intake is beneficial during any fat loss phase. This enables you to preserve more muscle and burn more fat over time. So protein has to be relatively high for optimal results, regardless of whether you go low- or high-carb. In this article, I show you how much protein you should eat per day.
The studies that suggest the ”supremacy” of low-carb diets, didn’t take the importance of protein intake into consideration. In this study, a low-carb, high-protein diet was compared to a high-carb, low-protein diet. The low-carb group did better, but was this because of the low-carb or the high-protein intake?
To answer this question, we need to turn to studies that equate protein intake between groups.
Here are a few more examples:
- Research by the Harvard School of Public Health, found no significant difference between low, moderate and high-carb diets.
- Research by the University of Arizona, found no significant difference between a low- and high-carb diet.
- Research by the Arizona State University, also found no significant difference between a low- and high-carb diet.
Basically, a low-carb diet is generally beneficial for fat loss due to an increase in protein intake. So as long you consume sufficient protein and are in a caloric deficit, it doesn’t seem like your carb and fat intake matter all too much for fat loss, which is great because it allows flexibility.
So, Is Low-Carb Useless?
While writing this article, I have assumed that you are in relatively good health, train often, and are not severely obese. If that’s true, it’s highly unlikely that you will achieve inferior results by eating carbs.
But some people genuinely find it easier to get lean by using a low-carb approach. If you are one of them, you should feel free to maintain a low-carb diet, as long as it consists of mostly nutrient-dense foods.
For example, in this study, some volunteers lost more fat with a high-carb approach, whereas some volunteers lost more fat with a low-carb approach. On average, low-carb dieting doesn’t deliver superior or inferior results, but you might find that this is different in your case.
When insulin resistance comes into play
If you’ve been severely overeating on carbs (or in general) for the last couple of years, research shows that there is a great possibility that you are experiencing issues with the metabolization of carbohydrates.
If you can relate to this, research shows you can benefit from reducing your carbohydrate intake. This likely has much to do with the fact that severely obese individuals often are insulin resistant.
Whether you choose to maintain a high-, moderate- or low-carb diet, you will be able to achieve great fat loss results if you are in a caloric deficit and consume sufficient amounts of protein.
If you want to learn more about how you can determine your macronutrient needs and how to approach your fat loss phase, I recommend you check out my free “Fat Loss Checklist.” I will send it to your email if you fill in the form below.