Weight loss: At what age does the metabolism begin to decline and how it affects weight loss?

When it is about weight loss, your metabolism plays a crucial role in burning calories. The higher the metabolism, the more calories you will burn and faster would be your weight loss. You can indeed speed up your metabolism by eating healthy, exercising and following healthy lifestyle habits, but there are some factors which you cannot control like your age. Your metabolism decreases with age that's why it becomes harder for older adults to shed kilos. It is believed that one's metabolism is at its peak during the teenage years when one can eat anything they want without the fear of gaining kilos. By the time they reach midlife around the 30s and 40s, it starts to decline, and it becomes difficult to keep the weight off. In contradiction to this popular theory, a new study suggests that our metabolism starts to decline much later in life. That means we cannot actually blame it for expanding waistline in midlife.

For the study, Herman Pontzer, PhD, associate professor of evolutionary anthropology at Duke University and an international team of scientists analysed the average calories burned by more than 6,600 people. It was conducted on people from 1 week to 95 years old in about 29 countries worldwide. The objective of this study was to understand how the human body changes over the lifespan. Here is what their finding suggests.

The study clearly indicated that babies and toddlers burn the highest amount of calories in a day. They have the highest metabolic rates of all. The researchers found out that energy consumption among babies increases after the first birthday and they start burning calories 50 per cent faster for their body size than an adult.

In the teenage days, overall metabolism slows down by 3 per cent compared to what it is before puberty. It remains the same till the age of 20 when it again speeds up. The researchers were surprised by the outcome as there were no drastic changes in the daily calorie intake during this phase. They were expecting a rise in the metabolic rate due to puberty and menopause, but that was not the case.

The finding of the study suggests that people in middle age certainly gain weight and it is harder for them to lose it, but slow metabolism is not the real reason behind it. It was revealed that from the 20s to the 50s the energy expenditure is the most stable. Even during pregnancy, there is no significant change in the number of calories burnt daily.

Your metabolism actually begins to slow down after you hit the mark of 60. It declines at the rate of 1 per cent per year till you reach 90. By the time a person reaches the age of 90, they burn about 25 per cent fewer calories than what they used to do in their midlife. Researchers believe that this could be due to loss of muscle mass.

Your metabolism does not have an impact on the weight loss process, but it is not responsible for weight gain in your midlife. Your lifestyle and underlying disease could also play a part in it.