Each person has a unique profile that determines where they are more likely to store excess fat.
Love handles, wobbly belly, beer gut - the fat around your tummy is a revealing marker of your true health.
Losing weight, which usually equates to losing fat, is a health goal for millions, and for good reason. According to NHS data, UK hospital admissions linked to obesity have doubled in six years to more than 1.2 million in 2022-23.
According to other government statistics published in 2023, 63.8 per cent of British adults in the year to 2022 were estimated to be overweight (with a BMI between 25 and 29.9) and over a quarter (25.9 per cent) were estimated to be obese (with a BMI over 30). We are getting fatter as a nation and the toll this takes on our health, and consequently on the NHS, is becoming intolerable. Indeed, Britain’s weight problem is costing almost £100 billion a year in healthcare costs and lost productivity.
Carrying too much fat is a risk factor for a range of chronic diseases, including cardiovascular disease, Type 2 diabetes, at least 12 kinds of cancer, liver and respiratory disease; it can also have an impact on mental health.
Undoubtedly, excess fat can be fatal, but the health impact depends on the amount of fat you carry, and crucially on where on your body it’s stored.
Not all fat is created equal and not all fat is unhealthy. Everyone carries fat. A normal body fat percentage for a woman between 20 and 79 is between 33 and 36 per cent, and for men of the same age it is between 19 and 25 per cent. There are also several types of fat in the human body, including brown fat: metabolic tissue that generates heat and helps burn other types of fat. Other fats are activated during pregnancy.
The most abundant type of fat, however, and the one most people attempt to lose when they embark on a weight loss programme is white fat, which can either be stored subcutaneously (under the skin as the type of fat you can pinch) or inside the body and specifically around the heart and organs in the abdominal cavity, where it is called visceral or intra-abdominal fat.
Each person has a unique fat storage profile that determines where they are more likely to store excess fat. Women are predisposed to store fat around their hips and thighs in the classic pear shape. Men are more likely to store fat around their middle (apple shape).
The evolutionary reason for this is that women’s bodies need to gain weight and hold on to calories in stable storage sites away from internal organs which can be mobilised when needed for breastfeeding, whereas men need fat stores that can be quickly metabolised into energy when hunting.
Crucially, we have a storage limit and when our subcutaneous fat “depots” are full, the fat accumulates inside as visceral fat, which is the most dangerous type of fat. It has been linked to heart disease, stroke, Type 2 diabetes, cardiovascular disease, Alzheimer’s and several types of cancer. It can also lead to inflammation and scarring of the liver, as Dr Martin Whyte, the associate professor of metabolic medicine at University of Surrey, explains.
“Visceral is by far the most dangerous. A key point is its relationship to the liver, which is the most important metabolic organ in the body. When you eat a meal, the fat contained in it passes into the bloodstream in the abdomen and most of that blood goes straight to the liver. Other fat stored in your abdomen also goes straight to the liver which is then constantly cycling fat, causing metabolic mischief.”
Visceral fat disrupts hormones and chemicals. For example, it releases a protein called fibroblast growth factor-2 (FGF2), which stimulates the growth of cells that can turn malignant. It can also increase levels of oestrogen, which can lead to an increased risk of breast and endometrial cancer in women. Additionally, visceral fat can increase levels of insulin and insulin-like growth factor (IGF-1), which can promote the growth and spread of cancer cells. Research also indicates that visceral fat produces proteins that inflame tissue and organs and narrow blood vessels, increasing blood pressure and the risk of heart disease.
Philip Chant is the director and founder of body composition scanning company Bodyscan, which holds the UK’s biggest body composition dataset of over 20,000 individual scans.
He explains that while subcutaneous fat is easy to see, visceral fat is harder to assess.
“Because it’s unseen, it can sometimes be quite a surprise for people when they discover how much they have. While obesity and high levels of subcutaneous fat are usually a good indication that someone is carrying visceral fat, some people can appear slim but still have significant amounts of internal fat.”
While your fat ratio is determined by a range of factors - including the amount of physical activity you do and the number of calories you consume, and whether you drink excessively and smoke - your fat distribution is more hardwired.
Dr Whyte explains: “Your pattern of fat tissue storage is genetic and also heavily influenced by hormones, so the ageing process affects that. Younger men have higher testosterone levels than older men and testosterone potentially lowers fat. As you get older, testosterone reduces and that facilitates more fat being stored around the abdomen.
“Women are genetically programmed to have more fat than men because they have babies and produce breast milk. Their fat is mainly stored in inert depots around the buttocks and thighs, which is described as a gynoid distribution. However, as they go through the menopause, they start to store more fat around the abdomen. Oestrogen has a clear effect.”
The World Health Organisation states that a waist circumference of 94 centimetres in men and 80cm in women is associated with an increased risk of metabolic complications. However, waist size is not always an accurate measure of visceral fat, as some people can have low levels of subcutaneous fat and higher levels of visceral fat.
The most accurate way to determine body composition is with imaging equipment such as CT, MRI or DEXA scanners, which are used by Bodyscan.
However, measuring your hip-to-waist ratio can provide an indication of your visceral fat risk. Simply measure your waist circumference halfway between the lower ribs and the top of your hip bone and measure your hip circumference at the largest point around the buttocks, then divide the waist by the hip measurement. Units do not matter as it is only the ratio that is important. High risk is defined as a waist-hip ratio above 0.90 for males and above 0.85 for females.
Softer around the hips
This is known as gynoid distribution, Chant says. “Men who have thigh fat revealed by DEXA scans are often surprised because thigh fat is usually firm, like muscle.”
Whyte cautions: “The gynoid shape in men can indicate a pathologically low testosterone level, suggesting there is a metabolic problem.”
Dangerous visceral fat
In bellies you’d typically see in men with high levels of visceral fat, “the skin around the extended belly is pulled tight like a drum”, Chant says. “Everywhere else looks relatively lean. For someone with this profile, I would recommend increasing exercise in addition to calorie deficit, because although you cannot target a specific area from which to lose fat – it happens across the whole body – visceral fat responds to exercise.”
Whyte adds: “Exercise is thought to preferentially remove visceral fat and particularly high intensity or aerobic training. At Surrey [University], we have done studies which suggest this type of activity does seem to preferentially remove abdominal fat.”
Fat all over the body
Chant assesses: “The fat distribution here ... shows all over the body - in the arms, chest and legs. Although [a man with this body type] has a high level of subcutaneous fat and doesn’t have that classic tight ‘drum’ belly fat effect, he’ll almost certainly have a high level of visceral fat.
“When a person is [very] big the best way to lose weight is to cut calories to start with because the weight will limit the range of activity you can do. People of this size often suffer joint and mobility problems. There is nothing healthy about it.”
Classic pear shape
Chant says: “This is a classic pear shape with fat stored on the legs, thighs and hips ... this is healthier than having a high level of visceral fat because the fat stores are better there than inside the abdomen.”
This is the usual fat storage pattern for a premenopausal woman, but that pattern changes as women go through menopause.
While gynoid subcutaneous fat carries less risks than visceral fat, Whyte cautions that any excess levels of fat can “carry a health consequence”.
Concerning apple shape
This is a more android pattern of fat distribution which can lead to more visceral fat and a higher risk of Type 2 diabetes, heart disease and stroke.
Chant says: “This shift from the classic female pear shape to the more male apple shape happens from menopause and beyond when women ... can put on weight in the belly and upper body.”
While weight gain and a change in body shape with age is a normal female physiological process, younger women who are already starting to develop stores of belly fat should be careful, as visceral fat levels can increase dramatically with menopause.
Excess fat all over
All-over fat in women, including in the upper body, suggests significant levels of visceral fat in addition to mobility issues.
Fat levels too low
Chant says: “There is a healthy threshold for fat. Low levels of fat for women can start to affect periods and cause fertility problems.”
Increase your NEAT
Jack Claxton, personal trainer at David Lloyd Clubs, explains: “In simple terms NEAT is non-exercise related activity. It all helps burn calories and involves making simple choices like choosing to take the stairs, going for a walk at lunch or deciding to cycle nearby rather than drive.”
Set a goal
“Ask yourself how you would like to see yourself in three months, six months, a year even,” says Claxton. “How will you look and feel if you achieve that goal? Think about what’s motivated you. Is it family and friends trying to encourage you to lose fat, or is it internal motivation? Keep focused on the goal and the reasons for it and remind yourself if you start to go off track.”
Read the labels, do the maths
An average man needs around 2500 calories a day to maintain his weight. For an average woman, that figure is around 2000 calories a day. If you are particularly overweight, the only way you’ll start to shift fat initially will be through calorie deficit, and that means smaller portions and eating the right types of food.
Learn about foods and calories. Read the labels on the foods you are eating. Chant explains: “If you are carrying 50 to 60kg of body fat, the fast inroads are going to be made by a fairly significant reduction in calorie intake. To lose 40kg of weight will likely take nearly two years with a 500-calorie deficit.”
Be careful of supposedly healthy nuts
Whole nuts are a great source of healthy fats and other nutrients, which is why people often choose them as a healthy alternative to snacks such as crisps and chocolate. But they are also loaded with calories – 100g of nuts contains 600 calories.
Switch up your exercise routine
Add some resistance training to your regular cardio work in order to build muscle, which is metabolic tissue and so burns more calories than fat. Try to start some form of high-intensity interval training (HIIT). If you exercise at home, you can find lots of free guided video sessions online, either with or without equipment. Most gyms also have their own classes.
However, don’t fall into the trap of allowing yourself to indulge because you’ve exercised – you’ll just be undoing the hard work.
A sex educator has answers on the ins-and-outs of sexual intercourse.