Lose weight to breathe more, or breathe more to lose weight

In the Christmas issue of BNJ magazine, a study conducted by researchers at the University of New South Wales in Australia shows that a majority of weight is released as carbon dioxide, out of the respiratory system. Remarkably, the study posits that this process attributes to weight loss.

This comes as a surprise for nutritionists and scientists, who study common knowledge on this topic. Common knowledge is that fat, also known as lipid, is converted to energy and heat, or stored as reserves in the body’s adipose tissue. The body stores fat to compensate for the energy that is used during muscle contraction and metabolism.


If this new study proves to be true, it could provide new knowledge on a global epidemic that is affecting billions of people. WHO reports that in 2008, more than 1.4 billion adults, worldwide over the age of 20 were overweight. On a more daunting note, obesity in children has more than doubled over the last 30 years. It is a growing issue for low and high-income countries and is a leading cause of type 2 diabetes, heart disease, stroke, and cancer.

According to the research, excess protein and carbohydrates are converted to a blood lipid, known as triglyceride. Triglycerides are composed of three molecules: carbon, hydrogen, and oxygen. These molecules are broken down by oxidation. When this oxidation occurs, about 10kg of fat is oxidized, and about 8.4kg is converted to carbon dioxide, then excreted through the lungs. This means that losing weight is actually an attempt to metabolize these triglycerides.

Interestingly, the researchers calculate that 17,280 breaths during the day will release at least 200g of carbon, resulting in close to a third of carbon emission during 8 hours of sleep. From this reasoning, weight loss depends on limiting the foods and drinks that would add additional carbon, such as fruit drinks and soda.

Though these findings are not completely new to science, this study shows new connections between breathing and weight loss. However, this is not the equivalence of an easy button. Weight loss will not happen because a person breathes often or a certain way. People have been breathing since birth, and obesity is still a worldwide health epidemic, which results in fatal illnesses. The focus on weight loss should not be on the weight itself, but on the person’s behaviors—such as comfort food eating habits, a lack of a nutritionally dense diet, and a lack of exercise.


Ones weight is a combination of the adipose tissue in the body and the bodies composition. This study only proves that weight loss depends on what is being put into the body through habit, and what is coming out of the body through nutrition breakdown and physical activity. Behaviors that help calorie intake meet daily energy output will create a balance between the amount of carbon that is released and the amount consumed. In addition, adhering to physical activity, such as exercise, reduces waist circumference, central obesity, and health risks.


Subsequently, it increases metabolic rates, which can release at least 40g of carbon. Overall, making these healthier choices can result in about 240 g of carbon released.