If you read these studies, one of the most amazing parts is how the participants lose as much as 3 times more weight than those who are on other diets, including calorie controlled, low fat diets. Yep, the same low fat diets that the government is recommending don't help people lose weight nearly as well as a low carb diet.
To top it all off, there are no side effects or unwanted health problems from eating a low carb diet on a long term basis. In fact, the opposite appears to be true, with many studies (1) showing that subjects had significant improvements in many areas, including lower blood sugar levels, lower triglyceride levels, yet higher HDL (the good) cholesterol levels.
Almost all low carb diet subjects had lost most of their weight in the belly and from around the liver, lowering their risk of fatty liver disease, inflammation, and the development of other diseases (2). This is especially good news for those who suffer from Type 2 diabetes and/or metabolic syndrome.
Although there is no doubting that these types of diets work tremendously well, there is some controversy concerning why they actually work.
Chances are that there are several reasons why low carb diets work so well, so we are going to take look at the most plausible explanations.
You might think that insulin is only something diabetics need to be concerned about, but the truth is that insulin in important to everyone when it comes to understanding body fat. Insulin is what regulates blood sugar levels, as well as fat (energy) storage.
This is the main hormone responsible for telling fat cells to both produce and store fat, hold on to the fat they carry, or release some for energy needs. It also tells other cells to either burn the sugar that is currently in the blood, or to store it.
It is the insulin that stimulates the production of fat (called lipogenesis) and inhibits the burning of fat (Lipolysis).
Low carb diets lead to drastic reductions in insulin. Less insulin means less stored fat. Dr. Atkins, Gary Taubes, and many others believe that is these lower levels of insulin, which are the driving force behind the effectiveness of low carb diets.
During the first ten days to two weeks of a low carb diet, people tend to drop weight very quickly. One of the main reasons for this is a loss of water.
We lose water due to two processes:
Lower levels of water in the body are a good thing. This doesn't mean you are dehydrated, this is simply excess water that is removed, and which means lower blood pressure, bloat, and unneeded extra pounds.
A low carb diet means protein will reign supreme at mealtime. Foods such as grains, bread, pasta, and sugar will now be replaced with protein, such as eggs, fish, and meat.
Protein has been proven in studies to reduce appetite, increase metabolism, and increase muscle mass, which burns more calories (3).
Some experts believe it is higher muscle mass, high metabolism, and higher protein that people consume, which feels the weight loss of low carb diets.
There is no denying that those consuming a low carb diet have a metabolic advantage over those eating a low fat or low calorie diet.
Some experts believe that low carb diets increase energy expenditure (by boosting the metabolism and increasing muscle mass) so that you lose more weight than any low calorie diet can match.
In fact, one study (4) found that a very low carb diet increased the expenditure of energy more than a low fat diet; as much as 250 calories more every day. That's equal to about one hour of exercise every day!
A very low carb diet is often called a ketogenic diet because when carb consumption drops to a certain point, the body starts to transform protein into gluconeogensis. This wastes a great many calories, which is another source of weight loss.
Numerous studies (5) have found that the higher the variety of food available, the more people eat. Low carb diets don't allow for a huge variety of food, so people tend to eat less of what is available to them.
Food is also a tremendous reward system. Low carb diets tend to leave out all those fattening foods that we normally turn to as a reward, such as donuts, cake, pie, etc.
By limiting “rewarding” (sometimes called addictive) foods, as well as the variety of food, the number of calories is greatly reduced, as well as insulin levels.
Another fact about eating more protein is that it significantly reduces the appetite. Studies (6) have proven that eating low carb diets cause appetite suppression, which causes people to eat fewer calories.
In studies (7) which compared low carb diets and low fat diets (which often have their calories restricted) the low carb dieters are usually allowed to eat until they feel full. Even then, the low carb groups lose more weight.
Besides the fact that protein tends to make people feel full for a longer period of time, the state of ketosis also tends to have an appetite suppressing action. In some studies (8), people in a state of ketosis felt that they only wanted to eat once or twice a day, because they simply weren’t hungry.
Although study after study has shown that low carb diets are very effective in helping people lose weight, the truth is that it seems to only work for a short period of time (about 6 to 12 months on average).
After that 1 year mark (give or take a few months) the difference between low carb diets and low fat diets is pretty much the same.
Most experts believe that the problem isn't the diet, but that people tend to get bored and abandon it once they have lost a certain amount of weight or after a certain period of time. This tends to be the case in every diet, not just low carb eating plans.
Although some people simply won't believe that low carb diets work (because it shatters their "calorie in/calorie out" belief), the fact is that numerous studies show that it does work.
Once you understand the mechanism behind low carb diets, you will see that the laws of thermodynamics still apply and that insulin is perhaps one of the main drivers behind the weight loss.
Low carb diets increase your metabolism, participants tend to eat less for a variety of reasons, and they build more muscle mass, which cause the body to increase the amount of calories it burns.