it does not slow down after the age of 40 and does not vary between men and women- breaking latest news

The metabolism does not slow down with middle age or even with menopause: therefore the weight gain, which often men and women from 40 years onwards, only due to lifestyle habits.

Revolutionary discoveries

It would be a significant distortion of the concepts on energy expenditure that have guided nutritionists and doctors so far and could come from the results of a new study conducted at the Duke University of North Carolina (USA) and published on Thursday Science. Research argues that metabolism can be divided for all people in four stages distinct of life and, in particular, slows down for everyone after 60 about e there are no differences of calorie consumption between men and women.

What Metabolism Measures

But what is metabolism? the amount of energy (measured in calories) consumed every day by our body and derives from the sum of 2 factors: the basal metabolic rate e work metabolism.
Basal metabolism is the energy expenditure at rest necessary to maintain the vital functions of the organism (breathing, heartbeat, blood circulation, minimal activity of the nervous system, etc.); it burns about 55-70% of the daily caloric requirement and a function that varies according to age, person’s build, genetics, sex, lifestyles.
The working metabolism is the sum of the energy expended in movement and in the assimilation of foods. The energy expended in physical activity varies according to the type, frequency and intensity of training and burns about 20-40% of the daily caloric requirement. The energy spent on digestion of meals burns about 10% of the daily calorie requirement.

The results

Duke’s study, led by Herman Pontzer, an evolutionary anthropologist, along with 80 other researchers who agreed to share their data, combined the efforts of half a dozen laboratories collected over 40 years and put together characteristics about the changes. in the metabolism in the course of life, taking into consideration almost 6,500 people, aged between 8 days and 95 years, across 29 countries around the world. The expensive metabolic research and thus most of the studies published so far had had very few participants. Hence the need to bring them together.

The examination determined that there are four stages of human metabolism:
– childhood, up to the age of 1 year: calorie consumption at its peak, accelerating to exceed the adult rate by 50%;
–youth, from the age of 1 to about 20 years: the metabolism slow down gradually about 3% per year (without increases in pubertal age from 10 to 15 years);
–l and adult, from 20 to 60 years: the metabolism is maintained stable (even in pregnancy);
–seniority, after the age of 60: metabolism it decreased by approximately 0.7 per cent per year.

The surprises about women and age

The main news is that, once the researchers have checked and balanced people’s body size and amount of muscle in the equations, they found no differences between men and women, while it was always thought that women had a slower metabolism. Furthermore, despite the undeniable (and sometimes noticeable) differences between people, a constant rate of energy expenditure per kg of weight has not been found, but energy expenditure depended on age. The group expected adult metabolism to start slowing at age 40 or, for women, with the onset of menopause, but, Dr. Pontzer said: We didn’t find that. The metabolic slowdown begins around age 60 and results in a 20% drop in metabolic rate by age 95. Although people gain more than one and a half pounds a year on average during adulthood, they can no longer attribute it to slowing metabolism. College students may also see the effects of metabolic change in their early 20s – by the time they finish school, they will burn fewer calories than when they started.

The expert: Valid values, but to be declined on the basis of individuals

The research findings could reshape the science of human physiology and have implications for some medical practices, such as determining appropriate drug doses for children and the elderly, but especially in terms of nutrition.

The study is very interesting and with great results for 2 reasons – explains Stefano Erzegovesi, Psychiatrist and nutritionist, director of the Center for Eating Disorders of the San Raffaele Hospital in Milan -: multicentre, therefore with a recruitment in various countries of the world, uses a technique of measuring metabolism (water marked with heavy isotopes) very expensive, laborious to do, but with the utmost reliability. The proposal of 4 life stages with different metabolisms will certainly be of help to all clinicians who deal with nutrition and weight.

Are there any limits to studying?
All the results reported on the metabolism are “fat-free mass and fat-mass adjusted”, therefore they report the functioning of our “motors in the cells” correcting the data in relation to our body composition. Which means: in the “ideal world” the mathematical model used in the study, the values ​​are certainly valid; in the “real world” of individual human beings, a 20-year-old with 16% fat mass certainly works differently from a 50-year-old with 25% fat mass. Furthermore, the metabolism values ​​are very “dispersed” in the population examined by the study, so there is a lot of variability between one subject and another. One more reason, in the real world, to consider the uniqueness of the single subject, explains the expert.

How to summarize the results seen?
As always happens with innovative scientific studies, the conclusions are to be welcomed with attention, bearing in mind that the values ​​of the metabolism have been “purified” by the variable “body composition”. On the other hand, let us read these data with moderate optimism for the rest of us in middle age: even if we were over 50 and were no longer kids, we could still usefully work to keep fit, with little fat mass. In doing so, the metabolism of a 50-year-old would not be so different from that of a 20-year-old, concludes the specialist.