Identification of obese patients who can benefit from weight loss is the right strategy in managing their health.  These include

1. Patients with a BMI of >27 with obesity related comorbidity
2. Patients with a BMI of >30 with or without comorbidity

The following tools maybe of use to you –

BMI – the most common diagnostic tool

The BMI table measures body weight relative to height for both men and women
(BMI = kg/m2), and is the most common diagnostic tool used in treating obesity.

Measuring the patient's BMI allows physicians to classify patients into groups and assign appropriate therapy based on the severity of excess weight..

However, BMI is only an indirect measure of body fat, and, at any given BMI number, women will have a higher percentage of body fat than men. For patients with a BMI less than 35 kg/m2, waist circumference should also be recorded. Waist circumference is an indirect measure of central adiposity and is correlated with visceral fat; a measurement greater than 40 inches in men and greater than 35 inches in women places patients at high risk for obesity-related comorbidities.

Table. Classification of Overweight and Obesity by BMI

Adapted from Clinical Guidelines, National Heart, Lung, and Blood Institute

BMI table

Click Here to Enlarge BMI Table

Click Here to Enlarge BMI Table

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Bioelectric Impedance Analysis  (BIA)

In this method, a weak alternating electrical current is passed through the body from 4 electrocardiogram electrodes, 2 placed on the hand and 2 on the foot. Because muscle conducts electricity and fat is an insulator, the electrical impedance measured provides an estimate of body water, which is translated into an estimate of lean body mass and body fat. BIA also provides resting metabolic rate, since each pound of lean body mass burns about 14 calories per day.

This method allows the differentiation of overweight individuals with low body fat, such as athletes, from overweight individuals with excess body fat. In some cases, the BMI will classify a hypermuscular individual as overweight, and body composition analysis will confirm that the person is in fact overweight but not overfat. By contrast, there are some individuals, older women in particular, with seemingly normal weight and normal BMI who may be suffering from reduced muscle mass. These individuals can be identified as overfat but not overweight by body composition analysis.

Body composition analysis helps patients understand the relationship between lean body mass and resting metabolic rate and to establish an appropriate target weight. Patients with increased lean mass will have a higher-than-average target weight and should be encouraged to maintain their lean body mass by exercising and adhering to adequate dietary protein intake. They must also be encouraged to accept their target weight, which may be higher than what they would like based on more traditional height and weight charts. Individuals with reduced lean body mass and a relatively low target weight should be encouraged to increase lean body mass through resistance exercise, which will in turn raise metabolic rate.

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Body Fat Distribution

Adipose tissue accumulation is referred to as body fat distribution. For individuals with android (apple-shaped) distribution, fat is centered around the abdominal area. This leads to an increased risk for coronary artery disease, stroke, diabetes, and high cholesterol and triglyceride levels. It is also an indicator for obesity. Gynoid (pear-shaped) distribution is associated with body fat that accumulates around the hip and thigh region.

Specific body fat distribution is often determined by measuring the waist-to-hip ratio, which is the circumference of the waist divided by the circumference of the hips. Android fat distribution is defined as a ratio greater than 1.0 for men and 0.8 for women.

Visceral fat is different from other body fat. Visceral fat, also called intra-abdominal fat, refers to the fat that surrounds the internal organs. Subcutaneous fat, on the other hand, is body fat that is close to the skin's surface and is considered less dangerous, and easier to lose, than visceral fat.

Studies have shown that those with visceral fat are more susceptible to heart disease, stroke, diabetes and hypertension. Sedentary people, smokers and drinkers have been shown to have more intra-abdominal fat, or visceral fat, than active people who are non-smokers and non-drinkers. Stress may also be a factor in the storage of visceral fat on the body.

Visceral fat is harder to lose than subcutaneous fat because it is more deeply embedded in the body's tissues. Visceral fat is only measured accurately by an imaging machine that can see how much of the abdomen is made up of visceral fat. A person may be within a healthy weight range, but still have too much intra-abdominal fat around the internal organs.

The liver metabolizes visceral fat and releases it into the bloodstream as cholesterol. Harmful, or "bad" cholesterol, which is Low-Density Lipoprotein (LDL), builds up into a plaque that blocks the arteries. Losing weight through proper diet and effective exercise can help reduce visceral fat. How much fat a person eats does matter as studies have shown that those who eat 30% or more of their diets as fat usually have high amounts of visceral fat.

Walking is considered by many health and fitness experts to be a much better way of helping to control visceral fat than by doing exercises such as swimming where gravity keeps the body afloat. Walking at a fairly fast pace for a half an hour six days a week has been shown to help reduce visceral fat, while walking only three days a week has not been shown to have much affect on the reduction of visceral fat. However, doing no exercise at all has shown to increase the amount of visceral fat in the body.

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Waist to Hip ratio

waist to hip ratio is an important tool that helps you determine your overall health risk. People with more weight around their waist are at greater risk of lifestyle related diseases such as heart disease and diabetes than those with weight around their hips. It is a simple and useful measure of fat distribution.

Use a measuring tape to check the waist and hip measurements.
- Measure your hip circumference at it's widest part.
- Measure your Waist Circumference at the belly button or just above it.

The Waist to Hip Ratio Calculator indicates your probable health risks. People with more weight around the waist, face more health risks than people who carry more weight around their hips.

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Waist Circumference

What is Waist Circumference?

According to the National Institutes of Health, a high Waist Circumference (WC) is associated with an increased risk for type 2 diabetes, dyslipidemia, hypertension and cardiovascular disease when the BMI is between 25 and 34.9. (A BMI greater than 25 is considered overweight and a BMI greater than 30 is considered obese.) Waist Circumference can be useful for those people categorized as normal or overweight in terms of BMI. (For example, an athlete with increased muscle mass may have a BMI greater than 25 - making him or her overweight on the BMI scale - but a Waist Circumference measurement would most likely indicate that he or she is, in fact, not overweight). Changes in Waist Circumference over time can indicated an increase or decrease in abdominal fat. Increased abdominal fat is associated with an increased risk of heart disease.

To determine your Waist Circumference, locate the upper hip bone and place a measuring tape around the abdomen (ensuring that the tape measure is horizontal). The tape measure should be snug but should not cause compressions on the skin.

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Age related weight gain

Many people who did not have any trouble maintaining a normal weight during their 20s and 30s find themselves struggling with weight in their 40s and 50s. The following are several factors that contribute to age-related weight gain.

• Changes in basic body processes
In general, our body runs slower as we get older. Basic body processes don’t require as much energy, which lowers your BMR.

• Less activity
Muscle requires more energy to maintain than body fat does. Therefore, the more muscle you have, the higher your BMR. But people tend to be less physically active in their 40s and 50s than they were in their younger years. With less physical activity, muscle mass decreases, lowering the number of calories needed.

• No change in appetite
Unfortunately, there is not an age-related decline in appetite to accompany the reduced calorie needs. If you eat the same amount as you did before, in the face of a slowing BMR, you will gain weight.

• Hormonal changes
With age, men experience a gradual decline in the hormone testosterone. Less testosterone in men has been shown to reduce muscle, causing the BMR to decline. Postmenopausal women may experience a similar effect from lack of estrogen. Animal studies have shown that a lack of estrogen leads to excessive weight gain, although the exact mechanisms are not yet understood.