When it comes to defining a healthy weight, most of us refer to body mass index, or BMI.
This number is a weight-to-height ratio measure used internationally by doctors to indicate a person's risk of a variety 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 more and more research now suggests that this conclusion is not necessarily true.
Several nutritionists are advocating for a new definition of healthy weight – which depends on our stage of life.
In November, the British Dietetic Association recommended in official advice that people over 65 should remain “slightly overweight”.
For a healthy young adult woman aged 20 to 39, body fat should be between 21 and 32 percent of her total weight
“If you are slightly overweight, losing weight may not actually improve your health,” the document says.
A few extra pounds can protect bones from fractures and fractures that are common with age – and help resist diseases that can lead to rapid weight loss.
And it's not until later in life that a few extra pounds are considered healthy. Some experts have argued that carrying more fat is particularly beneficial for women in young adulthood – and even middle age.
Here we will tell you the healthiest size for your stage of life.
First, it is important to understand the importance of body fat measurement, which is different from BMI.
As we age, the composition of our body changes – meaning we have a different ratio of muscle to fat – and we store fatty tissue in different parts of the body.
And experts say body fat measurements are more likely to provide an accurate risk of lifelong disease compared to BMI.
Most doctors advise seniors to lose extra pounds – but this could reduce older people's resistance 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 a man's.
On average, fat makes up about 18 to 20 percent of body weight in normal, healthy women. In men it is around 10 to 15 percent.
And as the body ages, muscle mass and bone density decrease, hormones change, metabolism slows, and fat is distributed differently throughout the body
HEALTHY FAT CONTENT FOR TEENAGERS
Teenage girls experience their body fat accumulating primarily in their thighs and hips during puberty, when their hips widen and breasts develop.
Your recommended body fat percentage is in the range of 25 to 28 percent.
Men, on the other hand, tend to have lower body fat percentages compared to women, due to differences in hormones, muscle mass and fat distribution.
Teenage girls should have a higher percentage of body fat than men during adolescence because the sex hormone estrogen fuels fatty tissue in the breasts and hips
Testosterone, the male sex hormone, promotes muscle building, unlike estrogen, which increases fat reserves in women.
For teenagers, the healthy body fat percentage for boys is between 12 and 15 percent.
Muscle mass gain starts slowly but may not keep up with the overall growth rate, resulting in more fat reserves in this age group.
HEALTHY FAT LEVELS IN YOUNG ADULTS
For a healthy young adult woman aged 20 to 39, body fat should be between 21 and 32 percent of her 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 levels peaking when a man is in his mid-20s.
Greater weight at this point is likely due to more muscle and bone mass.
HEALTHY FAT CONTENT IN MID-LIFE
Middle-aged and menopausal women undergo a number of specific hormonal changes that affect fat storage.
When estrogen levels drop, fat tends to shift away from the hips and toward the stomach.
This leads to an increase in visceral fat – the type that accumulates around organs and increases the risk of metabolic and heart disease.
While fat on the hips and thighs can be converted into muscle relatively easily, visceral fat is not.
For this reason, it is considered normal and healthy for a woman during menopause or after menopause to have a slightly higher body fat percentage.
The healthy body fat percentage for this age group is between 23 and 33 percent.
For middle-aged men, the healthy range is between 11 and 21 percent. At this point, fat tends to accumulate around the belly, a hallmark of the “daddy body.”
HEALTHY FAT LEVEL AFTER 65
Compared to young adults, older people tend to have a much lower percentage of muscle mass than their body weight.
They also typically have a slower metabolism, which promotes fat accumulation. But it turns out that might actually be a good thing.
Fat is a source of energy and therefore helps seniors survive periods of illness when they may not have an appetite.
It also helps protect against injury from falls, so weight loss instructions may be harmful.
A 2022 study on the ideal body mass index range for older adults concluded that older adults with a BMI below 25 were at higher risk of functional decline and had gait and balance problems, a risk of falls, a decrease in muscle strength, etc. suffered from malnutrition.'
According to the study, the optimal BMI range 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 standard BMI categories are too low for all ages, says the BDA's advice is a “good start.”