Obesity

Definition:

This is a condition defined by the Body Mass Index BMI

Cause and scope of prevention:

An imbalance between calorie intake and calorie expenditure.

Diagnosis:

The BMI is the usual criterion used but people with high levels of muscle have high BMI levels even though they would not be regarded as ‘fat’ and for this reason there is growing interest in using the body fat percentage as the best means of assessing how obese someone is.

The NHS website is clear 

For most adults, a BMI of:

• 18.5 to 24.9 means you're a healthy weight
• 25 to 29.9 means you're overweight
• 30 to 39.9 means you're obese
• 40 or above means you're severely obese

BMI is not used to diagnose obesity because people who are very muscular can have a high BMI without much fat. But for most people, BMI is a useful indication of whether they're a healthy weight.

A better measure of excess fat is waist size, which can be used as an additional measure in people who are overweight (with a BMI of 25 to 29.9) or moderately obese (with a BMI of 30 to 34.9). Generally, men with a waist size of 94cm or more and women with a waist size of 80cm or more are more likely to develop obesity-related health problems.

Standard medical therapy:

A small number of people who are severely obese benefit from gastric banding but for most people the advice is to reduce the intake of calories and to increase activity levels.

Types of and benefit of exercise:

Again, the NHS website is clear 

take up activities such as fast walking, jogging, swimming or tennis for 150 to 300 minutes (2.5 to 5 hours) a week

The key issue is motivation and support  

Key references:

1. Effect of exercise alone or combined with dietary supplements on anthropometric and physical performance measures in community-dwelling elderly people with sarcopenic obesity: A meta-analysis of randomized controlled trials.

Fidel Hita-Contreras 1, et a l  (2018)

DOI: 10.1016/j.maturitas.2018.07.007

Conclusion: Exercise improved muscle-related outcomes and reduced fat-related outcomes in subjects with sarcopenic obesity.

2. J Evid Based Med; 2017 May;10(2):108-128.

Exercise and BMI z-score in overweight and obese children and adolescents: A systematic review and network meta-analysis of randomized trials.

George A Kelley  

DOI: 10.1111/jebm.12228 

Free PMC article

Aim: Examine the effects of selected types of exercise (aerobic, strength training, both) on BMI z-score in overweight and obese children and adolescents.

Conclusions: Aerobic exercise and combined aerobic exercise and strength training are associated   with reductions in BMI z-score.

Effect of exercise alone or combined with dietary supplements on anthropometric and physical   performance measures in community-dwelling elderly people with sarcopenic obesity: A meta-analysis of randomized controlled trials

https://www.maturitas.org/article/S0378-5122(18)30416-X/fulltext 

Exercise and BMI z‐score in Overweight and Obese Children and Adolescents: A Systematic Review and Network Meta‐Analysis of Randomized Trials

https://onlinelibrary.wiley.com/doi/abs/10.1111/jebm.12228