When it comes to defining a healthy weight, most of us refer to the body mass index, or BMI.
This figure is a measure of the ratio of weight to height, which is used internationally by doctors to indicate a person's risk of a large number of diseases.
And we've long been taught that a BMI between 18.5 and 24.9 is healthiest, giving us the best possible chance of preventing diseases like diabetes, heart disease and even some cancers.
But now a growing number of studies show that this conclusion is not entirely true.
Several nutrition scientists have started calling for a new definition of healthy weight – one that depends on our stage of life.
In November, official advice from Britain's British Dietetic Association recommended that people over 65 should remain 'slightly overweight'.
For a healthy young adult woman ages 20 to 39, body fat should make up between 21 and 32 percent of their total weight
“If you are slightly overweight, losing weight may not actually improve your health,” read the document.
A few extra pounds can protect bones from fractures and fractures that often occur in old age – and help resist diseases that can cause you to lose weight quickly.
And it's not just later in life that a few extra pounds are considered healthy. Some experts have argued that for women in particular, carrying more fat is beneficial in young adulthood – and even middle age.
Here we reveal the healthiest size for your stage of life.
First, it is critical to understand the importance of body fat measurements, which are different from BMI.
As we age, the composition of our bodies changes – meaning we have a different ratio of muscle to fat – and fat tissue is stored in different parts of the body.
And experts say body fat measurements likely provide a more accurate lifetime risk of disease compared to BMI.
Most doctors urge seniors to shed extra pounds, but this can reduce an older person's resilience to injury and illness.
Women have a higher body fat percentage than men at all stages of life. Not because they are less healthy, but because the female body stores fat differently than that of a man.
On average, fat represents about 18 to 20 percent of body weight in normal, healthy women. In men, this represents approximately 10 to 15 percent.
And as the body ages, muscle mass and bone density decrease, hormones change, metabolism slows, and fat is distributed differently in the body.
HEALTHY FAT LEVEL FOR TEENS
Teenage girls going through puberty, a time when their hips widen and breasts develop, find their body fat collecting mainly around their thighs and hips.
Their recommended body fat level is in the range of 25 to 28 percent.
Men, on the other hand, tend to have lower body fat percentages than women, thanks to differences in hormones, muscle mass and fat distribution.
Teenage girls should have a higher percentage of body fat than men in adolescence because the sex hormone estrogen drives the fatty tissue in the breasts and hips
Testosterone, the male sex hormone, promotes muscle building, unlike estrogen which increases fat storage in women.
As for teens, the range of healthy body fat percentage for boys is between 12 and 15 percent.
Muscle mass begins to build slowly but may not keep pace with overall growth rates, leading to increased fat storage in this age group.
HEALTHY FAT LEVEL IN YOUNG ADULTHOOD
For a healthy young adult woman ages 20 to 39, body fat should make up between 21 and 32 percent of their total weight.
For young men aged 20 to 39, the healthy range is higher: between eight and 19 percent.
At this stage, hormones continue to fluctuate, with testosterone reaching its peak levels when a man is in his mid-20s.
A greater proportion of weight at this point is likely due to greater muscle and bone mass.
HEALTHY FAT LEVELS IN THE MIDDLE OF LIFE
Middle-aged and menopausal women undergo a specific set of hormonal changes that affect the way fat is stored.
As estrogen levels drop, fat tends to shift from the hips to the abdomen.
This leads to an increase in visceral fat – the type that builds up around organs and increases the risk of metabolic and heart disease.
While fat around the hips and thighs can be converted into muscle with relative ease, visceral fat cannot.
For this reason, it is considered normal and healthy to have a slightly higher body fat percentage for a menopausal or post-menopausal woman.
The healthy body fat percentage for that age group ranges from 23 percent to 33 percent.
In middle-aged men, the healthy range is between 11 and 21 percent. At this point, fat tends to collect around the abdomen, a characteristic of the 'dad body'.
HEALTHY FAT LEVEL AFTER 65
Seniors typically have much less muscle mass in relation to their body weight than young adults.
They also tend to have a slower metabolism, which promotes fat accumulation. But it turns out this might actually be a good thing.
Fat is a source of energy, so it helps seniors get through periods of illness when they may not have an appetite.
It also helps protect against injuries from falls, which can make weight loss counseling potentially harmful.
A 2022 study on the ideal body mass index range for older adults concluded that older adults with a BMI lower than 25' were at higher risk for a decrease in functional capacity and walking and balance problems, fall risk, decrease in muscle strength and problems experienced. malnutrition.'
According to the study, the optimal BMI level for older adults is 31 to 32 and 27 to 28 kg/m2 for women and men, respectively.
Katherine Flegal of Stanford University in California, who has long argued that the standard BMI categories are too low for all age groups, says the BDA's advice is a “good start”.
