Being overweight or obese is associated with a wide range of serious health conditions. The research is clear and consistent: excess body weight increases the risk of numerous diseases, reduces quality of life, and shortens lifespan. However, the good news is equally clear — even modest weight loss produces significant health improvements.
The Most Serious Health Risks
Type 2 Diabetes
Obesity is the single largest risk factor for type 2 diabetes. Excess fat — particularly around the abdomen — causes insulin resistance, where the body's cells stop responding normally to insulin. Most people diagnosed with type 2 diabetes are overweight or obese, and excess weight is the strongest modifiable risk factor for it.
Cardiovascular Disease
Excess weight raises blood pressure, increases LDL (bad) cholesterol, lowers HDL (good) cholesterol, and promotes inflammation — all major risk factors for heart attack and stroke. People with obesity have approximately double the risk of heart disease compared to those at a healthy weight.
Certain Cancers
Obesity is linked to at least 13 types of cancer, including breast, colon, endometrial, kidney, and liver cancer. Fat tissue produces hormones and inflammatory substances that can promote tumour growth. After smoking, obesity is the largest preventable cause of cancer in the UK and many other countries.
Sleep Apnoea
Excess fat around the neck and throat can obstruct the airway during sleep, causing breathing to repeatedly stop and start. This disrupts sleep quality dramatically, leading to daytime fatigue, impaired concentration, and increased cardiovascular risk.
Joint Problems
Every extra kilogram of body weight places approximately four kilograms of extra pressure on the knee joints. This accelerates the wear of cartilage, leading to osteoarthritis — one of the most common causes of chronic pain and disability in adults.
Non-Alcoholic Fatty Liver Disease
Excess fat accumulates in the liver, causing inflammation and potentially progressing to cirrhosis — serious liver damage. This condition is now one of the most common causes of liver disease in Western countries.
The Dose-Response Relationship
An important principle in understanding weight-related health risks is that higher BMI generally means higher risk, and the relationship is roughly dose-dependent: the more excess weight, the greater the risk. However, even being slightly overweight (BMI 25 to 27) carries measurably increased risks compared to a healthy weight.
Where Fat Is Stored Matters
Not all body fat is equally dangerous. Visceral fat — the fat stored around your abdominal organs — is metabolically active and produces inflammatory substances that damage blood vessels and organs. Subcutaneous fat, stored just beneath the skin, is much less harmful.
This is why waist circumference is an important measure alongside BMI. A waist over 88 cm in women or 102 cm in men indicates dangerous levels of visceral fat, even if BMI appears acceptable.
What Changes After Menopause
Everything above holds at any age. What changes at menopause is where the weight sits — and that changes the risk, even when the scales do not move.
As oestrogen falls, fat is redistributed away from the hips and thighs and towards the abdomen. The same kilograms become more visceral fat around the organs — the metabolically active fat described above. At the same time, lean muscle mass declines, roughly 1% a year for many women through the fifties, and resting energy expenditure falls with it. A woman can weigh exactly what she weighed at 45 and be carrying more of the fat that raises risk.
This is why BMI becomes a weaker guide after 50. BMI cannot tell muscle from fat, and after menopause the same BMI generally represents a higher proportion of body fat and a larger waist. A BMI of 26 at 58 does not describe the same body as a BMI of 26 at 28.
What to Measure Instead
Waist circumference is the more useful number in these years. Measure at the midpoint between your lowest rib and the top of your hip bone, after breathing out normally, without pulling the tape tight:
- Under 80 cm (31.5 in) — lower risk.
- 80 to 88 cm (31.5 to 34.6 in) — increased risk.
- Over 88 cm (34.6 in) — substantially increased risk.
Waist-to-height ratio is simpler still and works at any size: keep your waist below half your height. A woman of 165 cm is looking for a waist under 82.5 cm.
None of this changes what helps. The first 5 to 10% of body weight is where most of the measurable improvement sits — blood pressure, blood sugar, cholesterol, joint pain and sleep — and that holds after menopause as much as before it.
For the detail on protein, calcium and vitamin D in these years, see Nutrition & Supplementation in the Menopause 50+.
Sources and how to use this information
BMI is a screening measure, not a diagnosis or a direct measure of body fat. Health risks vary between people, and a BMI result should be interpreted with a qualified healthcare professional rather than used on its own to make treatment decisions.
The Good News: Even Small Improvements Help
The benefits of weight loss are not all-or-nothing. Research consistently shows that losing just 5 to 10% of body weight produces significant improvements in blood pressure, blood sugar, cholesterol levels, and joint pain. You do not need to reach a "perfect" BMI to see real health benefits.
Know Your Starting Point
Calculate your BMI now to understand where you stand and track your progress.
Calculate Your BMIMental Health and Quality of Life
The health effects of obesity extend beyond the physical. People with obesity are at significantly increased risk of depression and anxiety — partly due to social stigma, partly due to the direct effects of excess weight on mood-regulating brain chemistry. Addressing weight concerns compassionately, without shame or judgment, is essential for long-term success.