A study published in Science identified four age-related phases of the metabolism: it is very fast in the first year of life, then slows down little by little until the age of 20, remains stable between 20 and 60, and only slows down again in later life.
Metabolism changes
We get olderand ourmetabolismchanges. But perhaps not as much as we have always thought. The results of a major international study, published in Science, seem to undermine what little we thought we knew about the relationship betweenenergy expenditure,ageandgender. It is not true, for example, that women’s metabolism is slower than men’s, or that after the age of 20, energy expenditure changes so dramatically that it alone justifies weight gain. The research could have strong implications formedical practice, leading to a reassessment of the mostappropriatedoses of drugs, especially for children and the elderly.
It became clear that we didn’t have the right idea of how body size and ageing affect metabolism.”- Herman Pontzer, Duke University
The study
Metabolism research, explain the more than 80 scientists who authored the article, is very difficult and very expensive: until now, there was relatively little data and even the most reliable studies were often limited. To overcome this obstacle and try to unravel themysterysurrounding the relationship betweenmetabolism, age and gender,Herman Pontzerof Duke University set up an international collaboration of scientists who shared data on nearly6,500 peopleaged between8 days and 95 years, from 29 different countries.Using information on the energy expenditure, height, weight and percentage of fat and lean mass of the people involved, the researchers drew up apicture of metabolism trends in relation to the passage of time. At the end of the analysis, Pontzer commented, “it became clear that we didn’t have a good idea of how body size and ageing affect metabolism“.
The 4 stages of metabolism
What have the scientists discovered? It is true that the metabolism slows down with age, but not quite in the way we thought. In general, we can recognisefour metabolic phases: from 0 to 1 year of age; from 1 year to 20 years; from 20 to 60 years; and from 60 years onwards.The first metabolic “age”, up to thefirst year of life, is characterised by a very high energy demand: in this phase the metabolism travelstwice as fastas that of an adult. In other words, infants consume 50% more calories than adults for the same activities.After the first year of life, however,the metabolism begins to slow downa little at a time – by about 3% every yearuntil the age of 20. At that point,i.e. from age 20 to 60, the metabolismstabilises, and thengradually slowsdown by about 0.7% per year. Finally, from the age of 60 to 95, the metabolism drops by about 25%.
The research could have implications for medical practice, leading to a reassessment of the most appropriate drug doses, especially for children and the elderly
There are, of course, individual differences, but at population level the trend does not change, just as there are no differences in relation to genderor significant changes atpregnancyandmenopause, contrary to what might have been expected.
Stem cells. Cellular activity is highest during early childhood and gradually decreases over time, to the point of compromising the proper functioning of organs and tissues.
Metabolism and ageing
One possible explanation for how metabolism changes over time relates to how organs and systems change andthe energy demandfor their functioning. Not only dochildrenhave to supportgrowth and exercisemore, but they also havea larger brainthan an adult in proportion to their body size and havemore muscles(lean mass), two of the most energy-consuming organs of all. In general, then,after the age of 60, it isthe activity of all cells that gradually declines, which is responsible for the deterioration in organ function.
FAQs
A study published in Science identified four age-related phases of the metabolism: it is very fast in the first year of life, then slows down little by little until the age of 20, remains stable between 20 and 60, and only slows down again in later life.
How does metabolism change with age? ›
The slowdown is gradual, only 0.7% a year. But a person in their 90s needs 26% fewer calories each day than someone in midlife. Lost muscle mass as we get older may be partly to blame, the researchers say, since muscle burns more calories than fat.
At what age is your metabolism the fastest? ›
Researchers found that metabolism peaks around age 1, when babies burn calories 50 percent faster than adults, and then gradually declines roughly 3 percent a year until around age 20.
What are the metabolic aspects of aging? ›
Aging and Metabolism
Our bodies do not metabolize nutrients from food as efficiently, which can cause blood glucose levels to be elevated, particularly after we consume a meal. And anabolic processes such as building muscle protein become less efficient, so it's harder to gain muscle mass as we get older.
What are the 4 pillars of metabolism? ›
But that begs the question — where do you start to improve your metabolic health? And even more importantly, how do you build sustainable habits that you can stick to? This is where the Four Pillars come in. The Four Pillars are food (or nutrition), exercise, sleep, and stress.
What are the 4 functions of metabolism? ›
The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks of proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of metabolic wastes.
What foods speed up female metabolism? ›
Foods rich in protein, like lean meats, eggs and legumes, as well as fiber-rich foods, such as fruits, vegetables and whole grains, can help boost your metabolism.
At what age do females gain the most weight? ›
Poor diet, lack of physical activity, hormonal changes, and stress are some of the factors contributing to weight gain. Studies have revealed that women in their 30s are particularly susceptible to weight gain. Moreover, losing weight becomes more challenging at this age due to the progressive decline of growth.
What is the best metabolic age? ›
A good metabolic age should be roughly close to your age in real life. If you're 40, a healthy, balanced metabolic age will range between 35-45. Your metabolic age might read as younger than your actual age and that is fine — as long as it's not too low.
What are the 4 aging pathways? ›
The researchers determined that people generally age along certain biological pathways in the body: metabolic, immune, hepatic (liver) and nephrotic (kidney).
If your metabolic age is lower than your actual age, it means your body is in good health. If your metabolic age is higher than your actual age, it may mean you have health problems or may need to change your eating and exercising habits.
What is my metabolic age calculator? ›
You can use the Harris-Benedict Equation calculator or use the appropriate formula below: Male: 66.5 + (13.75 x kg) + (5.003 x cm) – (6.775 x age) Female: 655.1 + (9.563 x kg) + (1.850 x cm) – (4.676 x age)
What are the phases of metabolism? ›
The metabolism of drugs can occur in various reactions, categorized as phase I (modification), phase II (conjugation), and in some instances, phase III (additional modification and excretion). Phase III metabolism may also follow phase II metabolism, in which conjugates and metabolites are excreted from the cells.
What is type 4 metabolism? ›
Fast Metabolism – Type 4
It reflects increased metabolic activity due to increased adrenal and thyroid function. Sympathetic Dominance. Decreased Thyroid Function: A tendency toward decreased thyroid function and decreased secretion of hormones. Decreased Adrenal Activity: A decreased secretion of hormones.
What is Phase 4 of metabolic balance? ›
Phase 4 - Maintenance phase
You've reached your goals, you feel great and your metabolism has been reset. Maintenance is about ensuring you can maintain this level of health by continuing to make the right dietary choices for you.
