Obesity and Health - Monika Korngut's Delicious Living

Obesity

Disclaimer: All information provided should be considered as generalizations and not as specific information for any individual. Nor should this information be considered medical advice. This information needs to be considered in consultation with your family physician. Specific food allergies or medical conditions may make the provided information unsuitable for some individuals.

As physicians our goal is as much to prevent disease as it is to treat it once it has developed. Many tools have been demonstrated to have predictive value when it comes to future risk of disease. These tools allow doctors to educate patients on their specific risks modify the risk through specific strategies. Scientists follow large groups of individuals in research studies to determine what factors can predict a certain individual developing a certain disease. With years of research medical science is becoming more and more accurate in identifying your personal risk of certain disorders as you age.

One commonly used tool is the Body Mass Index or BMI. It is a ratio of an individual's weight in kilograms divided by their height in meters squared (see formula just to your right).

If your BMI is greater than 30. You are considered medically obese (not including children under age 18 and pregnant women)

The Health Canada BMI risk stratification chart is displayed to your right. The full nomogram and BMI calculator can be found on their website here.

**Health Risk Classification According to Body Mass Index (BMI)**
Classification	BMI Category (kg/m²)	Risk of developing health problems
Underweight	< 18.5	Increased
Normal Weight	18.5 - 24.9	Least
Overweight	25.0 - 29.9	Increased
Obese class I	30.0 - 34.9	High
Obese class II	35.0 - 39.9	Very high
Obese class III	>= 40.0	Extremely high

From the Health Canada Website

High BMI

So what does an elevated BMI put you at risk for?

An elevated BMI > 30 indicates an individual is obese.

Obesity has certain health consequences that have been demonstrated in clinical studies. Not only does obesity put you at risk for other risk factors (i.e. high blood pressure and high cholesterol) there are other serious complications. To your right you will find a list of the consequences associated with obesity and an individual's risk relative to the general non-obese population.

Health Consequences of Obesity

Greatly Increased Risk For:
(> 3x general population)

Diabetes
High blood pressure
High Cholesterol
Breathlessness
Sleep apnea
Gallbladder disease

Moderately Increased Risk For:
(2-3x general population)

Coronary heart disease (heart attacks) or heart failure
Osteoarthritis (of the knees especially)
Gout
Complications of pregnancy

Increased Risk For:
(1-2x general population)

Cancer
Impaired fertility
Low back pain
Increased risk during anesthesia
Fetal defects arising from maternal obesity

Overall, a healthy gradual weight loss of 10% of body weight in a obese individual will on average:

Drop systolic blood pressure by 10 mmHg
More than 20% reduction in death from all causes
More than 30% reduction in deaths related to diabetes
More than 40% reduction in deaths related to obesity

Source: Haslam, D., et al., British Medical Journal September 2006;Vol 333:640-642.

The BMI, as an indicator of risk, is independent and any additional risk factors such as high blood pressure, diabetes, smoking, excessive alcohol intake, high cholesterol or family history increase an individual's risk further. At the same time, if your cholesterol is normal and you have no other risk factors, it is still worth calculating your BMI to see if your weight is putting you at risk.

A recent study also showed a relationship between BMI and cognitive function.

2,223 healthy workers aged 32 to 62 at baseline and at follow-up five years later were subjected to cognitive testing. It was found that after adjusting for other risk factors, a high BMI correlated with a more significant decline in cognitive function on the tests used. Although this study needs to be replicated it is suggestive that obesity may play a role in future cognitive impairment (i.e. memory difficulty).

Source:
Cournot et al., Neurology October 2006;67:1208-1214.

BMI is NOT the whole story

Increased waist circumference (or waist size) is the most clinically suggestive indicator of concerning obesity and the waist-to-hip ratio also provides information.

Healthy conscientious eating in combination with regular exercise and check-ups with your family doctor best improves your chances of preventing future disease.

Dr. Lawrence Korngut, M.D.

Chief Neurology Resident
London Health Sciences Centre
London, Ontario, Canada