What is a healthy waist size, and why does it matter?
A larger waist is linked to a higher risk of early death, diabetes and heart disease, independently of overall body weight. If you also have other risk factors, it is sensible to discuss this with your doctor.
Belly fat is biologically active: it releases substances that drive inflammation, disrupt how the body handles sugar, and damage blood vessels. The deep fat that surrounds the internal organs is more harmful than the fat you can feel just under the skin. That deep belly fat throws the body's metabolism off balance more strongly, even when you account for overall weight or body mass index.
Every extra 10 centimetres of waist size is linked to an 11% higher chance of dying early, regardless of body mass index. The ratio between waist and hip size tells us even more: every increase of 0.1 in that ratio is linked to a noticeably higher risk of death. Strikingly, the opposite is true for fat on the hips and thighs: 10 centimetres more hip size is linked to a 10% lower risk of death, and 5 centimetres more thigh size is linked to as much as 18% lower risk. Fat on the hips and thighs therefore appears to be considerably less harmful than belly fat.
A large waist raises the risk of type 2 diabetes, even independently of body weight and blood test results. Duration also plays a role: having a large waist for many years causes risk to build up over time. For every 50 'waist-years', the risk of diabetes increases by 38%. The longer someone carries a large belly, the more harm accumulates.
Even so, a large waist size alone does not automatically identify who is most at risk. It is only when other risk factors are also present, such as high blood pressure or diabetes, that the risk becomes truly worrying. In those cases, the risk of heart disease or early death can more than triple compared with people who have none of those risk factors. In addition, being 'metabolically healthy' while carrying excess weight is often a temporary state: in roughly three quarters of people, that pattern eventually shifts to a less healthy picture with greater risks.
The studies behind this answer do not point to a specific number that marks the boundary between 'healthy' and 'unhealthy'. What they do show is this: the larger your waist, the higher the risk, and the longer it stays large, the more that risk grows. If you also have high blood pressure, raised blood sugar or unfavourable cholesterol levels, it is worth talking to your doctor about what your waist size means for you personally.
This answer draws on large studies in which people were followed over long periods, partly combined across dozens of such studies involving more than 2.5 million participants in total. The associations are consistent and strong; cause and effect have not been proven with certainty, but the evidence makes it plausible. The evidence on how deep belly fat works in the body is more solid: that mechanism is well established. The sources used say nothing about specific cut-off values.
What is a healthy cholesterol level and when should I be concerned?
A normal LDL value does not give a complete picture of your cardiovascular risk. Ask your doctor about your remnant cholesterol as well, especially if cardiovascular disease or Alzheimer's disease runs in your family.
What is a healthy HDL (good cholesterol) level, and can I raise it?
Raising HDL through lifestyle is possible, but your genes set the ceiling. Lowering triglycerides through less sugar and alcohol, more exercise, and weight reduction has the greatest effect.
How healthy are my blood vessels / what is my vascular age?
For a first impression of your vascular health, an ApoB blood test is the simplest and most accessible step; a CAC scan adds the most value when your risk remains unclear after blood testing.
What is a healthy resting heart rate?
A resting heart rate between 60 and 80 beats per minute is considered generally normal, but lower is fine for active people, and above 78 the risk begins to rise measurably. Exercise regularly, stop smoking, and do not let your heart rate creep up over the years.
What is a healthy ApoB level?
There is no fixed 'healthy' ApoB value, but below 82 mg/dL the risk of a stroke already decreases measurably. ApoB offers better protection than LDL alone, but discuss your personal target with your doctor, as it depends on your overall risk profile and any medication you may be taking.
What does your vascular age tell you about your health?
A high vascular age on the measurement is a serious signal: your risk of cardiovascular disease, dementia, and premature death is considerably elevated. Discuss it with your doctor, as there are lifestyle and medication options to slow arterial stiffness.