Obesity is defined as body mass index (BMI) greater than 29; while overweight is body mass index of between 25 and 29. Body mass index in other words is measured by dividing the weight of an individual in kilogramme with the square of the height of same individual in metres2 (kg/m2)

It has been observed that those who are overweight and obese tend to have increased chances of developing hypertension than their lean counterparts. It may not be clear why such difference exists, yet few factors have been postulated in an attempt to offer explanation to this. It is believed that those who are obese or overweight have a lot of fat which exerts some level of pressure on the blood vessels, thereby increasing the work load of the heart to overcome the pressure. This invariably increases the blood pressure which is the product of the cardiac output and peripheral resistance across the vessels.

Obesity and overweight are also linked to diabetes mellitus. This is because obesity suggests accumulation of many fat cells which are known to secrete some chemical substances, such as resistin and adiponectin, which are known to cause resistance to insulin. This means that the effect of insulin is minimized by those substances, thereby resulting to insensitivity of cells to insulin. This heralds and is the key thing in Type 2 diabetes mellitus. Researches have shown a verifiable relationship between obesity and diabetes mellitus.

 It is also noteworthy that obesity also predisposes an individual to coronary heart disease. This is via deposition of fatty tissues on the walls of blood vessels, thereby gradually and progressively leading to occlusion of blood vessels that supply the heart and subsequently a cut off of blood supply to the heart.

Obesity also has a close link with arthritis, particularlyosteoarthritis. Because obesity increases the weight, borne by the joints of the lower limbs, it obviously leads to some degenerative changes over time, which is more or less an adjustment to meet up with the task. This rather results to narrowing of joint space and sometimes bringing two bony ends in contact, thereby increasing friction and pains in the joints involved. This is why control of weight forms a core management protocol in osteoarthritis.

Therefore, combating obesity is essential in preventing a whole lots of chronic health conditions. This can be combated by exercise alongside dieting.