Overweight and obesity are perhaps the biggest risk factor for some of the biggest causes of death in Britain: heart disease, dementia and many types of illness. cancer.
Then there’s the impact of excess weight on the joints, bones and airways, increasing the risk of debilitating conditions such as arthritis and asthma.
Now, with the arrival of highly effective weight-loss injections, Britain is seeing more weight loss transformations than ever before. But can a sudden shift of a few stones undo the damage of years of obesity?
After all, the impact of extra weight is significant.
“Obesity generally leads to higher blood sugar levels, and this extra circulating sugar causes damage throughout the body,” says Stuart Gray, professor of muscular and metabolic health at New York University. Glasgow.
‘A large part of this damage affects the heart and blood vessels. If it develops into diabetesyou can damage your kidneys and nerves in the feet and eyes.
‘EToo high a body weight often also means that you have a higher level of fat in the blood, which can lead to plaques in the blood vessels, narrowing of the blood vessels and even more pressure on your heart.’
So at what point in life does this damage become permanent – regardless of a lifestyle change – and when is a healthy weight most crucial? Here, experts reveal life’s sweet spot when it’s best to be slim.
In Britain, almost two-thirds of adults are overweight, and over a quarter are obese
Keep a larger frame for less than ten years
According to a 2020 British study, the damage caused by carrying excess weight begins about five years after the onset of obesity.
However, after ten years, the risk of heart disease and heart-related death increases significantly.
A US study of 5,036 people found that those who were obese between the ages of five and 14 had a roughly 94 percent higher risk of premature death compared to those who had never been obese.
However, Professor Gray says that the danger also applies to people who have been overweight for a long time.
“The problem is the cumulative exposure to obesity,” he says. ‘If you’ve been overweight or lived with obesity for 10 or 15 years, the inflammation, vascular dysfunction [blood vessel damage] and high glucose levels will have caused damage that you cannot get rid of.”
However, he adds that being overweight for a longer period of time, such as 10 or 20 years or more, may be more dangerous than a shorter period of obesity.
“Someone who has been obese for five years may not have built up the same heart risk as someone in their 40s who has spent most of their life overweight,” he says.
Although joints and bones can be vulnerable to a short burst of extreme obesity, he adds.
‘A lot of excess weight can accelerate things like joint damage, which is difficult to recover from.’
Most critical decades for weight loss: your 20s, 40s and 50s
Experts agree that there are two points in life that are most crucial for getting in the best shape of your life, but for very different reasons.
Although the body has a “significant capacity to recover” from metabolic problems in your twenties, compared to other decades, this is the best time to adopt healthy living habits.
Dr. Mayoni Gooneratne, executive medical director at Personalized Health Clinics, says your 20s are the time in life when most people have very little reason not to pursue a healthy routine.
Age-related wear and tear is minimized, and time-consuming stressors such as childcare and leadership roles are less common.
Research shows that the earlier in life people start a healthy diet, the more likely they are to maintain it until mid-life and beyond.
‘In your 20s, establish a way of eating and exercising that you will enjoy repeating for decades,’ advises Dr Gooneratne.
‘It’s time to stop years of gradual weight gain and inactivity from becoming normal.’
Your 40s and 50s, also known as midlife, are an important time to make changes, experts say.
A British study published in the journal PLOS Medicine found that those who were obese for 20 to 30 years (usually starting around age 10) had a doubled risk of type 2 diabetes compared to those who were obese for just 10 years.
‘As you approach the 40s and 50s you see a much more dramatic increase in the risk to your health from being overweight or obese,’ says Professor Gray.
“While people should be thinking about their health earlier, if you haven’t already, once you get into that age group, you definitely want to start thinking about it.”
The Framingham Heart Study – an ongoing study of Americans’ cardiovascular health – found that the risk of obesity-related heart disease was 62 percent higher than average among people ages 50 to 74, compared to 37 percent higher among 25- to 49-year-olds.
An important reason for this is the hormonal changes that occur in this phase of life.
In women between the ages of 45 and 55, the decline in the sex hormones estrogen and progesterone caused by menopause can lead to weight gain, especially around the middle.
Visceral fat, the fat stored around organs, is strongly associated with insulin resistance, making it more difficult for the body to stabilize blood sugar levels.
‘Women start to lose muscle and bone at this age and the hormone change also starts to affect the health of the blood vessels,’ says Professor Gray.
‘These hormonal changes happen differently in men, but the downstream effects are largely similar.’
Midlife can also be a hectic phase.
‘Your work life can reach a peak and it’s very stressful, you become less active, you have more responsibility for caring for older parents and children, you just have a lot of demands on life,’ says Prof Gray.
‘All those things contribute to the metabolic risk; you gain some weight, you become less active, etc., and you end up in that vicious circle.’
The benefits of losing weight at this stage of life may be greater than in younger years, experts say.
Research published in the journal JAMA Network Open found that middle-aged people who lost excess weight had a 48 percent lower risk of developing a chronic disease than those who remained overweight.
This means that they developed chronic disease at about half the rate that they did not lose weight during the 23-year follow-up period.
This period is so crucial that the NHS offers a free health check every five years to people over 40, including waist measurements, blood pressure, cholesterol and sometimes blood glucose tests.
Promisingly, experts say there is no ‘point of no return’ when it comes to weight loss.
A 2010 US study found that a weight loss intervention for adults aged 69 to 75 halved the number of deaths in the group, which was said to result from an average fat loss of 10 pounds.
However, research has consistently shown that older adults who lose weight (over age 75) are more likely to die prematurely.
A 2024 analysis found that a 10 percent reduction in body mass index (BMI) in adults over age 65 was associated with a significantly higher risk of death over the next seven years.
Experts say this is likely because extra weight protects between ages 70 and 80 against frailty and falls, a leading cause of hospital admissions in old age.
In addition, extreme weight loss at this stage of life is often a sign of an underlying fatal disease, such as cancer.
Even among those who don’t develop fatal conditions, the benefit of weight loss is much less significant in people over 75 than in younger individuals, according to a 2014 meta-analysis of 20 studies.
So, if you’re about to lose weight, where should you start?
According to Prof Gray, portion control is crucial. ‘While quality of diet should of course be taken into account, most evidence is that quantity is the biggest problem when it comes to obesity,’ he says. “Compliment that with physical activity.”
Dr. Gooneratne adds: ‘Make most meals from vegetables, fruit, legumes, whole grains, nuts/seeds where necessary and protein.
‘Reduce your reliance on sugary drinks, snacks, takeaways and ultra-processed meals.
‘Incorporating regular walking or other exercise into daily life, alongside progressive resistance training, while emphasizing good sleep and reduced stress, will make a big difference.’
