Health, Food & Diet

Is weight a good indicator of health?

Imagine health as a continuum.  At one end you have severely underweight and at the other end severely overweight.  In most of these cases weight and health have a direct correlation.  But when you move more toward the middle ground the direct relationship between health and weight becomes less clear.

Within that middle ground common health conditions can affect people who are moderately overweight, moderately underweight or even normal weight.  

Why isn’t weight and health synonymous?

There are many controversies in the area of weight and health.  

According to research in the Journal of the American Medical Association being overweight may lead to a longer life.  The research was a detailed review of over 100 previously published research papers connecting body weight and mortality risk among 2.88 million study participants around the world.  The research confirmed that obese people tend to die earlier than those of normal weight, but the findings also suggested that people who are overweight (but not obese) may live longer than people with normal body weight.  The reasons why slightly overweight people may live longer are not yet clear. 

Another study by US and European researchers published in the European Heart Journal found that overweight and obese people were at no greater risk of developing or dying from heart disease or cancer, compared with normal weight people, as long as they were metabolically fit, despite their excess weight.  Being ‘metabolically healthy’ meant that participants did not experience insulin resistance or diabetes, low levels of good cholesterol, high triglycerides and high blood pressure.  Nearly half of the obese participants in the study qualified as metabolically fit and had no higher death risk than metabolically healthy normal weight participants. 

A third study – a comprehensive analysis published by the Centres of Disease Control (CDC) researchers in the Journal of the American Medical Association and led by Katherine Flegal PhD, looked at actual deaths in the US over a 30 year period.  This study found there were 7,931 more deaths annually in the two leaner groups (BMI 25 or lower), than in the two heavier groups (above a BMI of 25).

What these, and other studies, show is that our current common assumptions and understandings of weight and health are incomplete.

What are indicators of health?

There are many ways of measuring health.  Medical testing of blood pressure, blood sugars and blood fat and their ratios can be useful indicators.  Other signs of health are metabolic assessments such as having a waking body temperature of 36.5-37C, the ability to sleep through the night and wake up refreshed, having healthy looking skin and nails, regular and easy bowel movements, a healthy sex drive and for women a regular menstrual cycles with few symptoms.  Stable blood sugar, mood stability, good strength and muscles tone and a healthy immune system are also indicators of health.  And none of these markers are directly attributable to what you weigh.

How can I best improve my health?

Research suggests that becoming more active will have greater health outcomes than weight management alone.  

One of the greatest risks to our health is the amount of time we spend sitting.  A recent Australian study, published in the Archives of Internal Medicine, found that adults who sat for more than 11 hours a day or those who sat for 8-11 hours a day had a 40 percent and 15 percent increased risk respectively of dying within 3 years – from any cause – compared with those who sat for less than 4 hours a day. 

What was surprising is that the amount of time people spent exercising made no difference – it was the amount of time they spent sitting down.  

So when it comes to judging health, rather than using weight measurements, BMIs or subjective judgements based on appearance we should be learning to use test results, metabolic assessments and activity levels.