Lose weight with a low carb - high fat diet

Summary: Burn more calories with a low carb diet

Recent research has found that the energy burned by the body does not only depend on the calories that you eat but also on the type of nutrients (processed carbs such as starch and sugar; protein or fat) that you eat.

Eating a given amount of calories in a low-carbohydrate & high-fat diet makes your body burn more calories than the same amount of calories eaten in a high carbohydrate diet.

This means that the average man could lose an extra 20 lb (9 kg) of body weight over a 3 years by adopting this diet.

Lose weight and keep it off with a low carbohydrate diet

Research published one week ago (Ludwig, 2018) (1) confirms that eating more fat and fewer carbohydrates help the body burn more calories.

This study backs the claims of the high fat and low carbohydrate ketogenic diet.

The study involved a group of 164 adults (aged between 18 and 65 years), all of them with a Body Mass Index over 25 (meaning that they were either overweight or obese).

They were assigned at random to one of three types of diet with different content of carbs, which they followed for 20 weeks. The diets were:

1. High Carb (60% of the daily calorie requirements).
2. Moderate Carb (40%).
3. Low Carb (20%) and 60% from fat.

The protein content was the same percent value in all diets, and the energy content of each of these diets was adjusted to keep weight loss to no more than 4.4 lb. (2 kg).

Outcome

The results show that for every 10% decrease in carbohydrate input to the daily calorie requirements, the energy burned by the participants increased by 52 Cal. ⁄ day.

Those following the Moderate carbohydrate diet burned on average 91 Cal. ⁄ day more than those following the High Carb diet.

Even more calories were burned by those following the Low Carb diet: 209 Cal. ⁄ day.

Hunger hormone changes

Hormone levels also changed: Ghrelin and Leptin were lower in those eating the Low Carb diet in comparison to those eating the High Carb diet.

Ghrelin is released into the blood by the stomach when it is empty and travels to the brain. There, it acts on a control center in the brain called the hypothalamus and makes you feel hungry.

It also lowers energy expenditure and promotes the accumulation of fat in your body tissues. So lower ghrelin levels may inhibit appetite, make you burn more calories, and prevent fatty deposits.

Leptin on the other hand is released by the body's adipose tissue (fat cells). It drops when you fast and increases when you eat. Maybe lower levels of this hormone in those following the Low Carb diet indicates an improvement in leptin sensitivity.

The paper reports that people with "the greatest declines in leptin levels after weight loss have the lowest risk for weight regain." This is another benefit of the lower carbohydrate diet: lose weight and keep it off.

So, what does this mean?

Eating a High Carb diet makes the body burn more calories, and this could lead to an extra 20-pound weight loss for an average man over three years.

Because, if you burn more energy while eating the same amount of calories and you will have to get it from somewhere: your fat stores, therefore, you will lose weight.

So it isn't only counting calories (the participants in this study ate the same quantity of calories) it is where they come from that counts.

Metabolizing calories from fat or carbohydrates (sugars, refined starchy foods) are the key. Eating processed carbs increases your levels of insulin, and this makes the body burn fewer calories -and store the sugars as fat.

The participants' triglyceride levels increased as carbohydrate content grew (So High Carb participants had higher levels of triglyceride fat in their blood than the Low Carb group) and HDL (or "good" cholesterol) dropped which is another negative side-effect of eating a high carbohydrate diet.

What remains unclear however is what causes all of these effects: the lower Carb content? or the higher fat content?

In case you are wondering what types of food were included in the Low Carb diet, it had fruit, legumes, and vegetables, ensuring a good input of healthy carbohydrates and fiber. And it had no grains or added sugar.

References and Further Reading

(1) Cara B Ebbeling, David S Ludwig et al., (2018). Effects of a low carbohydrate diet on energy expenditure during weight loss maintenance: randomized trial. BMJ 2018; 363 DOI: https://doi.org/10.1136/bmj.k4583 (Published 14 November 2018)