Low carb: how it works
What are you designed to eat?
Humans evolved over millions of years as hunter-gatherers, without eating large amounts of carbohydrates. We ate the food available to us in nature by hunting, fishing and gathering all the edible foods we could find. These foods did not include pure starch in the form of bread, pasta, rice or potatoes. We have only eaten these starchy foods for 5 – 10 000 years, since the development of agriculture. Only a limited adaptation of our genes takes place in such a relatively short time.
With the Industrial Revolution, 100 – 200 years ago, we got factories that could manufacture large amounts of pure sugar and white flour. Rapidly digested pure carbohydrates. We’ve hardly had time to genetically adapt to these processed foods.
In the 80s, the fear of fat gripped the western world. Low-fat products popped up everywhere. But if you eat less fat you need to eat more carbohydrates to feel satiated. And it’s at this time in history that our disastrous epidemics of obesity and diabetes started. The most fat-phobic country in the world, the USA, was hit the hardest and is now the world’s most obese country.
Today, it’s clear that the fear of real food with natural fat contents has been a big mistake.
The problem with sugar and starch
All digestible carbohydrates are broken down into simple sugars in the intestines. The sugar is then absorbed into the blood, raising the blood glucose levels. This increases the production of the hormone insulin, our fat storing hormone.
Insulin is produced in the pancreas. In large amounts it prevents fat burning and stores surplus nutrients in fat cells. After some time (a few hours or less) this may result in a perceived shortage of nutrients in the blood, creating feelings of hunger and cravings for something sweet. Usually at that point people eat again. This starts the process again: A vicious cycle leading to weight gain.
On the other hand, a low intake of carbs gives you a lower, more stable blood glucose, and lower amounts of insulin. This increases the release of fat from your fat stores and increases the fat burning. This usually leads to fat loss, especially around the belly in abdominally obese individuals.
Weight loss without hunger
An LCHF diet makes it easier for the body to use its fat reserves, as their release is no longer blocked by high insulin levels. This may be one reason why eating fat produces a feeling of longer-lasting satiety than carbohydrates. It’s been shown in a number of studies: When people eat all they want on a low carb diet caloric intake typically drops.
So, no counting or food weighing is necessary. You can forget about the calories and trust your feelings of hunger and satiety. Most people don’t need to count or weigh their food any more than they need to count their breathing. If you don’t believe it, just try for a couple of weeks and see for yourself.
Health as a bonus
No animals in nature need the assistance of nutritional expertise or calorie charts to eat. And still, as long as they eat the food they are designed to eat they stay at a normal weight and they avoid caries, diabetes and heart disease. Why would humans be an exception? Why would you be an exception?
In scientific studies not only is the weight improved on a low carb diet – the blood pressure, blood sugar and cholesterol profile (HDL, triglycerides) are also improved. A calm stomach and less cravings for sweet food are also common experiences.
Initial side effects
If you stop eating sugar and starch cold turkey (recommended) you may experience some side effects as your body adjusts. For most people these side effects tend to be mild and last a just few days. There are also ways to minimize them.
Common side effects in the first week:
- Heart palpitations
The side effects rapidly subside as your body adapts and your fat burning increases. They can be minimized by drinking more fluids and by temporarily increasing your salt intake a bit. A good option is to drink some broth every few hours. Alternatively, drink a few extra glasses of water and put extra salt on your food.
The reason for this is that carbohydrate-rich foods may increase the water retention in your body. When you stop eating high-carb foods you’ll lose excess water through your kidneys. This can result in dehydration and a lack of salt during the first week, before the body has adapted.
Some people prefer to decrease their intake of carbohydrates slowly, over a few weeks, to minimize the side effects. But the “Nike way” (Just Do It) is probably the best choice for most people. Removing most sugar and starch often results in several pounds lost on the scale within a few days. It may be mostly fluids but it’s great for the motivation.
How low to go?
The less carbohydrate you eat the bigger the effects on weight and blood sugar will be. I recommend following the dietary advice as strict as you can. When you’re happy with your weight and health you may gradually try eating more liberally (if you want to).
More details: How low carb is LCHF?
Diet Doctor video courses
If you want more beautifully-packaged knowledge about a low-carb, high-fat diet (LCHF) there are many video courses on the membership pages (free trial one month).
Dr. Westman’s guide
The food revolution
The presentation above summarizes the history and science behind the ongoing low-carb revolution.
Learn much more about how low carb works in the videos below, about basic and more advanced topics:
Keep reading about questions and answers about low carb
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