Low-carb diets have gained huge popularity in the last 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 current scientific data, we will form an objective conclusion about 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 low at all times.
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 the muscles and stores the rest as fat, after food consumption.
Once insulin is released, your body’s ability to burn fat is suppressed and you will most likely gain 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 IntensiveDietaryManagement showcases this quite well.
To clear all potential confusion regarding this, here’s a simple example:
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 (2500/6=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 calorie 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 equals less fat gain, right?
First of all, research shows that your body is very capable of gaining fat when insulin levels are low. If this wasn’t the case, then you could eat unlimited amounts of dietary fat and stay lean. Fat gain due to excess dietary fat is caused by an enzyme called ”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 overtime. Fat accumulation is not a response to insulin spikes from carbohydrate consumption, it’s a response to systematically eating at a calorie surplus.
So for healthy individuals, insulin is not something you should 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 ”fat-reducing” benefits of low-carb diets stand ground. 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 most 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 concern.
We all 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 many different studies that a high protein intake is crucial during any fat loss phase. This enables you to preserve more muscle and burn more fat overtime. So protein has to be high, 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 indicate the ”supremacy” of low-carb diets, didn’t take the importance of protein intake into consideration. In this study, a high-fat, high-protein and low-carb diet was compared to a low-fat, low-protein and high-carb diet. The low-carb group did better, but was this because of the low-carb or the high-protein intake?
For more clarity, we need to turn to studies that kept protein intake relatively equal in all groups.
After searching for a few hours, I’ve found three studies that compared low-carb with moderate/high-carb dieting, while volunteers maintained the same (high) protein intake.
Let’s see the results of these studies:
- 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, this shows that it doesn’t matter whether you go low- or high-carb. These diets deliver similar results, when protein and caloric intake is matched.
When low-carb dieting can be more effective
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, then 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, then there is no reason for you to switch to a high-carb diet. There will always be a group of people that will react different than the rest.
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, then research shows you are probably better off with a low-carb approach. This is because severely obese individuals are often insulin resistant. This means that their cells don’t respond properly to insulin anymore.
Unless you have neglected your health for the last couple of years, a low-carb diet won’t have to burn more fat than a high-carb diet. You will achieve great results with both ways of eating, if you keep your protein intake high.
Since consuming carbs is something many enjoy, it sounds logical to me to maintain a moderate fat/carb and high protein intake. This provides the most enjoyment, while still achieving optimal results.
That is exactly what I teach in my free fat loss guide called: “The Maximizing Fat Loss Plan”. If you haven’t gotten your hands on this guide yet, I suggest you fill in the form below to get a deeper understanding on how fat loss works!