While most healthy people have a little visceral fat, problems arise when it exceeds 10 per cent of total body fat. - PHOTO: ST FILE
SINGAPORE (The Straits Times/ANN): Being obese can cause a wide array of medical problems – in fact, more than 200 of them – from stroke, heart attack and dementia to diabetes and kidney disease.
But the good news is that shedding those extra kilos can reduce the risks. The extent of the benefit varies with the amount of weight lost, said Dr Tham Kwang Wei, a senior endocrinologist at Woodlands Health.
Dr Tham, who is also president of the Singapore Association for the Study of Obesity, noted that an obese person who loses 10 per cent to 15 per cent of weight could see a significant improvement in health.
“As little as 3 per cent weight loss can result in improvement in diabetes control. However, for diabetes remission (or returning to a normal blood sugar level), typically a minimum of 15 per cent weight loss is required. It could possibly achieve normal blood sugar levels for diabetics,” she said.
Excess fat results from food consumption exceeding energy expenditure.
The damage caused by excess fat occurs when the normal fat storage area – the subcutaneous tissue just under the skin – is full. The extra fat then spills over to places where it is not supposed to be.
That is like “continuing to fill petrol into your car after the fuel tank is full”, said Professor Tai E Shyong, a senior endocrinologist at the National University Hospital.
“So it goes all over the place. It goes to places where it’s not supposed to be stored, like the heart, kidney and liver.”
The spillover fat, called visceral fat, sticks to the organs and even permeates them, impairing the functions of the organs.
While most healthy people have a little visceral fat, problems arise when it exceeds 10 per cent of total body fat.
Prof Tai said the muscles of organs cannot handle the excess fat. It is not just the added weight of fat clinging to the organs, the cells in the organs also react negatively to the fat, leading to further complications.
According to Dr Tham, fat in the wrong places could cause inflammation and oxidative stress, among other problems.
She explained that swollen fat molecules can produce proteins that trigger inflammation. Inflamed tissue may also harden and cause plaque, which can block the flow of blood and increase the risk of heart attack and stroke.
Additionally, oxidative stress arises from an imbalance of free radicals and antioxidants, leading to cell damage and contributing to conditions such as cancer, Alzheimer’s disease and heart disease. Severe oxidative stress could ultimately cause cell death.
Professor Tai E Shyong emphasised that not all problems affecting the organs are directly attributable to excess fat, since even thin people can also suffer from them. - ST PHOTO: ONG WEE JIN
Excess fat also produces adipokines or proteins that promote growth, potentially accelerating the growth of certain cancer tumours.
Both experts agreed that the easiest way to lose weight is to eat less, rather than exercise more. However, they stressed the importance of physical activity, as having greater muscle mass allows the body to burn fat more quickly.
Ways to reduce visceral fat include eating a healthy diet, fasting intermittently, exercising, reducing stress, limiting alcohol and getting more sleep – about 10 per cent of fat is used up during sleep.
Dr Tham suggested that people reduce the portion of each meal by 25 per cent. If they can maintain that, they will likely lose some weight. But she added that losing 10 per cent to 15 per cent of weight will be challenging without the help of medication.
A new class of glucagon-like peptide-1 (GLP-1) drugs can help people lose about 20 per cent of their weight by suppressing their appetite. Such a big loss would result in significant medical benefits.
Britain’s National Health Service announced on Oct 3 that it plans to offer US pharmaceutical giant Eli Lilly’s GLP-1 drug, called Mounjaro, to about 250,000 people over a three-year period.
Priority will go to obese people with a body mass index of at least 40, and who have minimally three weight-related disorders such as hypertension, Type 2 diabetes, sleep apnea and cardiovascular disease.
But Prof Tai emphasised that not all problems affecting the organs are directly attributable to excess fat, since even thin people can also suffer from them.
For some individuals, obesity may play a secondary role in their medical problems by exacerbating existing conditions. For example, obesity could worsen the bad effects of high blood pressure or high levels of cholesterol, increasing the risk of getting cardiovascular diseases such as heart attack and stroke.
Not everyone who appears obese suffer from the ill effects of excess fat. The two doctors said that some people have fat cells that can swell instead of spilling over into the surrounding tissue and causing problems.
This is why some obese people have normal blood sugar, triglyceride and insulin levels. Prof Tai estimated that between 10 per cent and 30 per cent of people fall into this metabolically healthy obese category.
Conversely, others who may not look very fat might start getting obesity-related conditions such as sleep apnea, gout and fatty liver disease, which could cause liver hardening and potentially require a transplant. This occurs because their visceral fat is not visibly evident.
Prof Tai, who eats only one meal on weekdays, said a recent study of overweight men found that a 10 per cent reduction in their weight resulted in a 60 per cent decrease in the fat in their liver. The study did not look at fat in other organs.
His theory is that weight loss results in fat reduction throughout the body, but with the bulk of it being visceral fat.
On the significant weight loss from GLP-1 drugs, Prof Tai said: “They’ve enabled us to do stuff in the clinic that we were never able to do before.”
He cited patients who, despite being “put on everything”, continued to have protein in their urine, a sign of kidney damage. However, after starting them on an older GLP-1 drug dulaglutide, the problem was resolved within three months. - The Straits Times/ANN
