Categories of Evidence

  1. Randomised controlled trials (Rich body of data)
  2. Randomised controlled trials (limited body of data)
  3. Non randomised trials observational studies
  4. Panel consensus judgement

Evidence based recommendations (6)

  1. Weight loss is recommended to lower elevated blood pressure in overweight and obese persons with high blood pressure (Category A).
  2. Weight loss is recommended to lower elevated level of total cholesterol, LDL cholesterol and triglycerides and to raise low levels of HDL cholesterol in overweight and obese persons with dyslipidemia (Category A).
  3. Weight loss is recommended to lower elevated, blood glucose levels in overweight and obese persons with non-insulin dependent diabetes (Category A).
  4. Practitioners should use the BMI to assess overweight and obesity. Body weight alone can be used to follow weight loss, and to determine efficacy of therapy (Category C).
  5. The BMI should be used to classify overweight and obesity and to estimate relative risk of disease compared to normal weights. (Category D).
  6. The waist circumference should be used to assess abdominal fat content (Category C).
  7. For adult patients with a BMI of 25-34.9kg/in2 sex-specific waist circumference cut offs should be used in conjunction with BMI to identify increased disease risks (Category C)
  8. The initial goal of weight loss therapy should be to reduce body weight by approximately 10% from baseline. With success, further weight loss can be attempted if indicated through further assessment. (Category A).
  9. Weight loss should be about 1-2 pounds per week for a period of 6 months, with the subsequent strategy based on the amount of weight lost. (Category B). 
  10. Controlled Diets are recommended for weight loss in overweight and obese patients. Reducing fat as part of a low calorie diet is a practical way to reduce calories Category A).
  11. Reducing dietary fat alone without reducing calories is not sufficient for weight loss. However, reducing dietary fat, along with reducing dietary carbohydrates, can facilitate calorific reduction. (Category A).
  12. A diet that is individually planned to help create a deficit of 500-1000 kcal/ day should be an integral pan of any programme aimed at achieving a weight loss of l-2lbs per week. (Category A).
  13. Physical activity is recommended as part of a comprehensive weight loss therapy and weight control programme because it:
    • Modestly contributes to weight loss in overweight and obese adults (Category A)
    • May decrease abdominal fat (Category B)
    • Increases cardio respiratory fitness (Category A)
    • May help with maintenance of weight loss (Category C)
  14. Physical activity should be an integral part of weight loss therapy and weight maintenance. Initially moderate levels of physical activity for 30-40 minutes, 3-5 days a week, should be encouraged. All adults should set a long-term goal to accumulate at least 30 minutes or more of moderate-intensity physical activity on most and preferably all days of the week (Category B).
  15. The combination of a reduced calorie diet and increased physical activity is recommended since it produces weight loss that may also may also result in decreases in abdominal fat and increases in cardio respiratory fitness (Category A).
  16. Behaviour therapy is a useful adjunct when incorporated into treatment for weight loss and weight maintenance (Category B).
  17. Practitioners need to assess patient motivation to enter weight loss therapy: assess the readiness of the patient to implement the plan and then take appropriate steps to motivate the patient for treatment. (Category D).
  18. Weight loss and weight maintenance therapy should employ the combination of low calorie diet, increased physical activity and behaviour therapy. (Category A).
  19. Weight loss drugs approved by the Medicines Control Agency (MCA) may be used as part of a comprehensive weight loss programme, including dietary therapy and physical activity for patients with a BMJ of greater than or equal to 30kg /m2 with no concomitant obesity related risk factors or diseases, and for patients with a BMI of greater than or equal to 25kg/in2, with concomitant obesity related risk factors or diseases. Weight loss drugs should never be used without concomitant lifestyle modifications. Continual assessment of drug assessment for efficacy and safety is necessary. If the drug is efficacious and helping the patient to lose and/or maintain weight loss and there are no serious adverse effects it can be continued. If not it should be discontinued (Category B).
  20. Weight loss surgery is an option for carefully selected patients with clinically severe obesity (BMI >40, or >35 with co-morbid conditions), when less invasive methods of weight loss have failed and the patient is at high risk for obesity associated morbidity or mortality (Category B).
  21. After successfull weight loss the likelihood of weight loss maintenance is enhanced by a programme consisting of dietary therapy, physical activity, and behavioural therapy which should be continued indefinitely. Drug therapy can also be used. However drug safety and efficacy beyond one year have not been established (Category B).
  22. A weight maintenance programme should be a priority after the initial 6 months of weight loss therapy (Category 13).
  23. Literature suggests that weight loss and weight maintenance therapies that provide a greater frequency of contacts between the patient and the practitioner and are provided over the long term should be utilised wherever possible. This can lead to more successful weight loss and weight maintenance. (Category C).
  24. All smokers, regardless of their weight status should give up smoking (Category A). Prevention of weight gain should be encouraged and if weight gain does occur, it should be treated through dietary therapy, physical activity, and behaviour therapy, maintaining the primary emphasis on the importance of abstinence from smoking (Category C).
  25. A clinical decision to forego obesity treatment in older adults should be guided by an evaluation of the potential benefits of weight reduction for day to day functioning and reduction of the risk of future cardiovascular events, as well as a patients motivation for weight reduction. Care must be taken to ensure that weight reduction programme minimises the likelihood of adverse effects on bone health or other aspects of nutritional status (Category D). The possibility that a standard approach to weight loss will work differently in diverse patient populations must be considered when setting expectations about treatment outcomes (Category B).

Weight management - some evidence