Obesity means having too much body fat. It is not the same as being overweight, which means weighing too much. A person may be overweight from extra muscle, bone, or water, as well as from having too much fat.
Both terms mean that a person's weight is higher than what is thought to be healthy for his or her height.
The two most common ways to measure health risks from your weight are:
Body mass index (BMI)
Waist circumference (your waist measurement in inches)
BMI is measured using height and weight. You and your health care provider can use your BMI to estimate how much body fat you have.
Your waist measurement is another way to estimate how much body fat you have. Extra weight around your middle or stomach area increases your risk for type 2 diabetes, heart disease, and stroke. People with "apple-shaped" bodies (meaning their waist is bigger than their hips) also have an increased risk for these diseases.
Skin fold measurements may be taken to check your body fat percentage. Blood tests may be done to look for thyroid or hormone problems that could lead to weight gain.
The world-wide explosion of overweight people has been called an epidemic. The inflammatory nature of obesity is widely recognized. Could it really be an epidemic involving an infectious agent? In this climate of concern over the increasing prevalence of overweight conditions in our society, investigators have focused on the possible role of oral bacteria as a potential direct contributor to obesity.
To investigate this possibility, the study's researchers J.M. Goodson, D. Groppo, S. Halem and E. Carpino measured salivary bacterial populations of overweight women. Saliva was collected from 313 women with a body mass index between 27 and 32, and bacterial populations were measured by DNA probe analysis. Levels in this group were compared with data from a population of 232 healthy individuals from periodontal disease studies. The median percentage difference of seven of the 40 bacterial species measured was greater than 2 percent in the saliva of overweight women. Classification tree analysis of salivary microbiological composition revealed that 98.4 percent of the overweight women could be identified by the presence of a single bacterial species (Selenomonas noxia) at levels greater than 1.05 percent of the total salivary bacteria. Analysis of these data suggests that the composition of salivary bacteria changes in overweight women.
It seems likely that these bacterial species could serve as biological indicators of a developing overweight condition. Of even greater interest, and the subject of future research, is the possibility that oral bacteria may participate in the pathology that leads to obesity.
