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Women who are overweight or obese but otherwise healthy are still at an increased risk of cardiovascular disease, a large study suggests.

The analysis tracked the health of 90,257 women in the US for up to 30 years.

Those with excess weight were likelier to have a stroke or heart attack, even if they had normal blood pressure and cholesterol and no diabetes, it found.

Researchers said it showed "healthy obesity is not a harmless condition".

Obesity affects almost all of the cardiovascular disease risk factors, such as high blood pressure, excess cholesterol and diabetes.

But some obese people do not appear to have these metabolic disorders, leading scientists to debate whether or not the excess weight actually raises their risk.

This new study found women who were overweight or obese (BMIs in excess of 25 and 30 respectively) but had none of these risk factors were 20% and 39% more likely to develop cardiovascular disease than women of a normal weight (BMI 18.5-24.9) who were metabolically healthy.

However, the authors said it showed an association rather than cause and effect, and was mainly in white women, meaning the findings cannot be generalised to other ethnic groups or men.

"Our large cohort study confirms that metabolically healthy obesity is not a harmless condition, and even women who remain free of metabolic diseases for decades face an increased risk of cardiovascular events," said Prof Matthias Schulze, from the German Institute of Human Nutrition Potsdam-Rehbruecke, who led the study.

Women who were a normal weight but metabolically unhealthy were around two-and-a-half times more likely to develop cardiovascular disease than women of the same weight who were metabolically healthy.

That risk was even greater in women who were overweight and obese, said the study, published in The Lancet Diabetes & Endocrinology journal.

Experts also found that the majority of metabolically healthy women developed either high blood pressure, excess cholesterol or diabetes as they got older, even if they were normal weight.

Fitness vs fatness

Prof Schulze added: "Our findings highlight the importance of preventing the development of metabolic diseases.

"They suggest that even individuals in good metabolic health may benefit from early behavioural management to improve their diet and increased physical activity in order to guard against progression to poor metabolic health."

Jeremy Pearson, associate medical director at the British Heart Foundation, added: "This large scale study confirms that obesity, even if unaccompanied by other warning signs, increases risk of cardiovascular disease in women."

However, Prof Carl Lavie, from the University of Queensland School of Medicine in New Orleans, who was not involved in the research, said he and colleagues had argued that "fitness is more important than fatness".

He noted that the study did not have precise data on the participants' physical activity and their cardio fitness.

He added: "It is prudent to remind ourselves that an ounce of prevention is better than a pound of cure."

BMI and obesity: Where are you on the UK fat scale?

Use this calculator to find out your own body mass index (BMI) and see how you compare with the rest of the nation. You will also get tips from health experts and useful links to information on how to improve your health.

Your browser does not support this lookup. Cannot retrieve data. Height cm Feet in cm ft/in Weight kg stone lb kg st/lb Age Age Gender Female Male Postcode Postcode Region Please choose Scotland Wales Northern Ireland the North East the North West the East Midlands the West Midlands Yorkshire and the Humber the East of England London the South East the South West Region Waist size (optional) i To measure your waist, find the bottom of your ribs and the top of your hips and wrap a tape measure midway between these points. Breathe out naturally before taking the measurement. Waist size (optional) Waist size (optional) cm in See how you compare Your BMI Your BMI is [bmi_result] which is in the [bmi_category] category. Healthy Overweight Obese Very obese Underweight 30 40 18.5 25 Healthy Overweight Obese Very obese Under- weight 30 40 18.5 25 BMI is a standard way of measuring if people are a healthy weight for their height. For most adults 18.5 to 24.9 is the healthy range. Your age group Your BMI is [comparative] the average of [bmi_score] for a [gender_singular] in your age group ([user_age_group]) in [user_country]. About [percent]% of [gender_plural] in your age group in [user_country] are overweight, obese or very obese. 0% Underweight 0% Healthy 0% Overweight 0% Obese 0% Very obese Your part of the UK In all parts of the UK, the majority of the adult population is overweight, obese or very obese, according to the latest national surveys. In [region], the figure is about [percentage]% of [gender_plural]. North East 50% West Mids 50% Scotland 50% East Mids 50% Yorks & Humb 50% N. Ireland 50% North West 50% South East 50% South West 50% East 50% Wales 50% London 50% 50% What does this mean for you? The information you've given us indicates you could be underweight. There can be health risks associated with a low BMI such as anaemia, osteoporosis, a weakened immune system and fertility problems. This is not a medical diagnostic tool so don't panic if this isn't the result you were expecting to see. If you're concerned about your weight, or your health in general, speak to a healthcare professional such as your GP. You're in the healthy range which is great. Research shows that having a healthy BMI can reduce your risk of serious health problems, such as type 2 diabetes, heart disease, stroke and some cancers. But not all people with a BMI in this range have a lower risk. Other factors such as smoking, high blood cholesterol or high blood pressure will increase your risk. If you're of Asian descent you have a higher risk of heart disease and diabetes at a lower BMI and waist circumference. A healthy BMI for you would be 18.5-23. We're more likely to gain weight as we get older so to stay a healthy weight you may need to make small changes to your diet or your activity levels as you age. The information you've given us indicates you are overweight. Research shows that a BMI above the healthy range can increase your risk of serious health problems, such as type 2 diabetes, heart disease, stroke, and some cancers. A healthy BMI for a person of your height would be 18.5-24.9. If you're of Asian descent you have a higher risk of heart disease and diabetes at a lower BMI and waist circumference. A healthy BMI for you would be 18.5-23. Losing even a small amount of weight, if sustained, can have a big impact. For most people changing your diet is by far the best way to lose weight. Activity can help you maintain your target weight, and can have other health benefits, but increasing activity alone is not nearly as effective as diet at helping you shed the pounds. Even small changes like reducing portion sizes or choosing lower calorie snacks and drinks can help you lose weight or stop putting it on. The information you've given us indicates you're in the obese category. Research shows that having a BMI in this range will significantly increase your risk of serious health problems, such as type 2 diabetes, heart disease, stroke, and some cancers. A healthy BMI for a person of your height would be 18.5-24.9. If you're of Asian descent you have a higher risk of heart disease and diabetes at a lower BMI and waist circumference. A healthy BMI for you would be 18.5-23. Losing even a small amount of weight, if sustained, can have a big impact. For most people changing your diet is by far the best way to lose weight. Activity can help you maintain your target weight, and can have other health benefits, but increasing activity alone is not nearly as effective as diet at helping you shed the pounds. There's lots of support available to help you make changes, either to lose weight or to stop putting on weight. The information you've given us indicates you're in the very obese category. Research shows that having a BMI in this range will significantly increase your risk of serious health problems, such as type 2 diabetes, heart disease, stroke, and some cancers. A healthy BMI for a person of your height would be 18.5-24.9. If you're of Asian descent you have a higher risk of heart disease and diabetes at a lower BMI and waist circumference. A healthy BMI for you would be 18.5-23. Losing even a small amount of weight, if sustained, can have a big impact. For most people changing your diet is by far the best way to lose weight. Activity can help you maintain your target weight, and can have other health benefits, but increasing activity alone is not nearly as effective as diet at helping you shed the pounds. If you are concerned, or would like to find out more, speak to your doctor or GP. If you are ready to make lifestyle changes, there is lots of support available. Your waist size BMI is not the only way of measuring whether you are a healthy weight. Doctors say that carrying too much fat around your belly can increase your risk of health problems. Excess fat in this area can stress internal organs - even if your BMI is in the healthy range. Your waist size is [size] For [gender_plural], the NHS says a waist size of: 80cm (31.5 inches) or more means an increased risk of health problems 88cm (34 inches) or more means a very high risk of health problems 94cm (37 inches) or more means an increased risk of health problems 102cm (40 inches) or more means a very high risk of health problems People from non-white ethnic groups may be at risk at a lower waist size How to check your waist with just a piece of string

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