Why Do Low Carb Diets Work For Weight Loss?

Why do low carb diets for weight loss work?… and they do… The really simple explanation is that if you take away carbs – then your body must burn it’s stored fat… which ultimately leads to weight loss.

This is how I often see low carb diets explained to me but there is quite a bit more to it than that…let’s find out more…

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Low Carb Diet for Weight Loss Conventional Approach

I think we’ve got an overwhelming body of evidence to suggest that low carb diet for weight loss do work.

Currently compared to low fat diets, low carb diets are winning 33 to nil, in terms of statistically significant weight loss in randomized control trials studies. Those are the gold standard of studies.

So why is that? Well, first of all, it’s because the conventional approach is simply flawed.

The conventional approach that you’ll no doubt be familiar with is the calories in calories out approach. Basically you’re consuming too many calories and not burning enough calories so you gain weight.

Of course the solution to that is to simply eat less, move more, create a calorie deficit.

Eating Healthy and Exercising but NOT Losing Weight

In the longer term,you’re going to find that your problems are solved except …..it doesn’t really work. Does it, because most people have real trouble sticking to a weight loss program.

Most people who do stick to a weight loss program lose minimal weight. Even if they do start to lose some weight then they’re probably going to put it back on within a year or two years.

The reasons are because our body fights back when we calorie restrict it,
our bodies aren’t stupid. We get more hungry and we reduce our metabolic rate.So you start to actually feel tired and you start to feel really, really hungry. It’s no wonder that people fall left their diets really quite quickly.

Dealing With Our Hormones

I believe these issues are properly addressed by the low carb approach because this deals with things on a hormonal level, rather than just basically thinking about just large energy stores.

I always encourage people to go back to basic biology and really think about what the human body is, which is a series of tissues and organs, and the way those tissues and organs communicate with each other is either by the nervous system or via hormones.

And it’s hormones that we’re going to focus on in this post because that’s what is really, really important in terms of why a low carb diet for weight loss really works.

Low Carb Diet for Weight Loss Reduce Insulin Levels

Now it has an impact on a number of different hormones but insulin is really, really important because it is our body’s fat storage hormone.

And what I mean by that is it actually is the signal to take glucose
from our blood stream, put it into our cells, into our fat cells, where it is turned into our stored body fat. Insulin is produced by the pancreas in response to elevated blood glucose levels, which shuttle that glucose from the bloodstream into the fat cells where it is stored. So elevated insulin levels equal fat storage.

Low carb diets address this because they reduce insulin production. It’s the carbohydrates, particularly the glucose that signals to the pancreas to produce more insulin.

If you take away the carbs, the insulin production is lower and those lower levels of insulin allow our bodies to access that stored fat rather than just storing more of it. This results in weight loss in two phases. In the first few days you’re going to lose mainly just water weight, But after a few days you’re going to start to be able to access those fat stores and actually use up that body fat for energy to supply your body and you’ll lose body fat.

Effect on our Kidney’s

The reason we lose water weight in the first few days is because insulin also has an effect on the kidneys,causing them to retain fluid, lower levels of insulin, meaning that the kidneys can lose fluid.

That’s one of the reasons why our blood pressure can go a bit lower when we’re on a low carb diet,which is generally thought of as a good thing.

The second reason is because our bodies store carbohydrate for the short term in the form of glycogen.

Effect on Glycogen Stores

Glycogen is stored in the liver and muscle and along with glycogen is stored water. So you start to burn through those glycogen stores, and after a few days, you will have burnt through them but you’ll also have lost the water that was stored along with them.

Insulin Resistance

The low carb diet is particularly important for people who are suffering with something called insulin resistance. Insulin resistance is where the body is actually resisting the effects of insulin. So it takes more insulin to have the same effect on the cell, which is to move blood glucose from outside in the blood into the cell itself.

And many of us who struggle with obesity have also got insulin resistance.

The two really go hand in hand and that means we’ve got much higher insulin levels a lot of the time and therefore are turning off our ability to break down fat.

Reduced Appetite

Another reason that low carb diets are so effective is because of reduced appetite. Now our appetite again is under hormonal control.

There’s lots of hormones that are involved in appetite regulation like leptin and ghrelin. I don’t want to go too much into those hormones here, but the sense of fullness that you get on a low carb diet is very very different from the sense fullness you get on a high carb diet.

The high carb diet is very much about the bulk of food that you eat. So you are full because you really can’t eat anymore and the stretch receptors in your stomach that are telling you that you are full.

Whereas on a low carbohydrate diet, you feel a lot more full because you are nutritionally satisfied, particularly proteins and fats are very filling on their own. Whereas carbohydrates, like I say, are really due to the bulk of the size of the food.

Hungry all the time

It’s very common for people who are suffering with obesity to tell me that they’re hungry all the time. I remember back when I was struggling with my weight that I couldn’t fill myself up at breakfast, not for very long anyway.

No matter what size bowl of cereal I’d have in the morning, and I had some pretty big bowls of cereal, I couldn’t really fill myself up. Then come 11 o’clock in the morning, I’d have a dip in energy and I would just need to eat something in order to keep me going until lunch.

It would be the same thing in the afternoon as well. However big of a lunch I’d had, I’d have a dip in the afternoon that I’d need to go and grab something, usually a sweet treat so I could function until the evening when I’d have my evening meal. So this is very, very common.

People tell me that whatever they eat they seem to be hungry fairly soon afterwards.

Intermittent Fasting

The reduced hunger that many people feel on a low carb diet is a gateway into intermittent fasting, which as you may be aware, is also an excellent way to lose weight.

Many people simply don’t feel hungry in the mornings when they’ve been on a low carb diet for a few days or a few weeks. If you start tuning into your hunger then you don’t really want to eat until around lunchtime. This means you naturally fall into a pattern of what we call 16/8 intermittent fasting, which is when you really only eat within an eight hour window. You may eat a larger lunch and a larger dinner, maybe seven o’clock in the evening.

This means you are actually fasting for a total of 16 hours overnight. Intermittent fasting is great because throughout that fasting period your insulin levels are going to be low and you’re going to be releasing your bodies to stored fat for energy.

Metabolic Advantage

And the third reason that low carb diets are so effective is because they appear to give us a metabolic advantage.

There was a fantastic study done in 2018 that I will link at the end. What they did was, they put several groups of people onto different diets in terms of carbohydrate content and looked at the metabolic advantage of each of the diets.

What I said about metabolic advantage is that the low carb diet group actually burned 200 calories a day more than a high carb group. So a pretty significant metabolic advantage simply by being on a low carb diet.Going to be burning about 200 calories a day more than somebody who’s on a high carb diet.

Food Addiction

The final reason low carb diets are so effective,and we’re starting to see more and more evidence that points towards this, is that low carbohydrate diets help with food addiction.

Now, I don’t want to go into why sugar and carbohydrates are obviously so addictive at this point in this post, but I’ve often heard people saying, oh, I could never go without pasta, I could never go without bread, I could never go without rice, or I could never go without cake.

On a certain level that’s an addiction!

Compare that to I could never go without alcohol or I could never go without cigarettes! Well, you’d easily say that that was an addiction, wouldn’t you?

It seems that less food addiction equals less consumption of these bad foods, which are obviously high in energy, and therefore leads to improved weight loss.


So that’s it really. I think it all comes back to hormones at the end of the day. I think understanding that our bodies are not just an energy store which needs to be calorie restricted, but a series of interconnected tissues, which communicate via hormones.

If we actually work with our body’s hormones then we’re going to be on to a winner. And that’s really the basis of why low carbohydrate diets work.