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Recommendations Summary

AWM: Medical Nutrition Therapy 2014

Click here to see the explanation of recommendation ratings (Strong, Fair, Weak, Consensus, Insufficient Evidence) and labels (Imperative or Conditional). To see more detail on the evidence from which the following recommendations were drawn, use the hyperlinks in the Supporting Evidence Section below.


  • Recommendation(s)

    AWM: Medical Nutrition Therapy

    Medical nutrition therapy (MNT) provided by a registered dietitian nutritionist (RDN) is recommended for overweight and obese adults. MNT provided by an RDN results in both statistically significant and clinically meaningful weight loss in overweight and obese adults, as well as reduced risk for diabetes, disorders of lipid metabolism and hypertension.

    Rating: Strong
    Imperative

    • Risks/Harms of Implementing This Recommendation

      None.

    • Conditions of Application

      Weight loss may be beneficial for other health conditions as well. In addition, the RDN should assess for appropriateness of weight management in certain populations (eating disorders, pregnancy, receiving chemotherapy, etc.).

    • Potential Costs Associated with Application

      Costs of MNT sessions vary, however MNT sessions are essential for improved outcomes.

    • Recommendation Narrative

      Recommendation Narrative from MNT Effectiveness

      • MNT provided by an RDN results in both statistically and clinically significant weight loss in otherwise healthy overweight and obese adults
      • Four studies regarding the effectiveness of MNT for under six months reported significant weight losses of approximately one to two pounds per week (Holm et al, 1983; Richardson et al, 2005; Schneider et al, 2005; Raatz et al, 2008)
      • Four studies regarding the effectiveness of MNT from six to 12 months reported significant mean weight losses of up to 10% of body weight (Eilat-Adar et al, 2005; Feigenbaum et al, 2005; Dengel et al, 2006; Digenio et al, 2009)
      • Four studies report maintenance of this weight loss beyond one year. In these studies, both individual and group sessions were employed with weekly and monthly sessions (Melin et al, 2003; Willaing et al, 2004; Ashley et al, 2007; Sacks et al, 2009).

      Recommendation Narrative from Diabetes

      • In randomized clinical trials, approximately half report improvement in A1C values with weight loss; whereas, approximately half report no improvement in A1C values despite fairly similar weight losses
      • A total of 12 studies with more than one diet arm (Hollander et al, 1998; Manning et al, 1998; Hanefeld et al, 2002; Miles et al, 2002; Kelley et al, 2003; Redmon et al, 2003; Brinkworth et al, 2004; Metz et al, 2004; Wolf et al, 2004; Li et al, 2005; Berne et al, 2005; Redmon et al, 2005) reported weight loss and A1C values at 12 months
      • Seven studies in diet arms reported no improvement in A1C (Hollander et al, 1998; Manning et al, 1998; Redmon et al, 2003; Brinkworth et al, 2004; Wolf et al, 2004; Li et al, 2005; Redmon et al, 2005) despite weight loss (range, -0.8kg to -4.4kg) in all but one study, which reported no weight loss (Manning et al, 1998)
      • Five studies in diet arms reported improvement in A1C ranging from -0.2% to -0.6% (Hanefeld et al, 2002; Miles et al, 2002; Kelley et al, 2003; Mertz et al, 2004; Berne et al, 2005) with fairly similar weight losses (range, -1.3kg to -5.1kg)
      • Studies using weight loss medications (orlistat and lifestyle, sibutramine) report consistent improvement in A1C. Six studies with an orlistat arm (Hollander et al, 1998; Hanefeld et al, 2002; Miles et al, 2002; Kelley et al, 2003; Derosa et al, 2004; Berne et al, 2005) reported improvements in A1C values (range, -0.3% to -1.1%) with orlistat and lifestyle intervention with weight loss (range, -3.9kg to -6.2kg).
      • Five studies (McNulty et al, 2003; Redmon et al, 2003; Derosa et al, 2004; Sanchez-Reyes et al, 2004; Redmon et al, 2005) reported improvements in A1C values (range, -0.3% to -6.0%) with sibutramine with weight loss (range, -4.1kg to -8.0kg)
      • A total of 10 studies reported significant improvements in at least one lipid value, generally in triglycerides and HDL-cholesterol from weight loss either by diet alone or with weight loss medications (Hollander et al, 1998; Hanefeld et al, 2002; Miles et al, 2002; Paisey et al, 2002; Ash et al, 2003; Kelley et al, 2003; McNulty et al, 2003; Metz et al, 2004; Berne et al, 2005; Li et al, 2005)
      • Seven studies reported improvement in blood pressure with weight loss (Miles et al, 2002; Redmon et al, 2003; Brinkworth et al, 2004; Derosa et al, 2004; Metz et al, 2004; Li et al, 2005; Redmon et al, 2005), however one study using sibutramine reported increases in blood pressure (McNulty et al, 2003) and one study using sibutramine reported no change in blood pressure (Derosa et al, 2004).
      Recommendation Narrative from Disorders of Lipid Metabolism
      • A total of 10 studies provide evidence that:
        • An increased BMI and waist circumference are associated with increased risk of metabolic syndrome
        • In the metabolic syndrome patient, a cardioprotective dietary pattern (low in saturated fat, trans fat and cholesterol, limited in simple sugar intake and increased in consumption of fruits, vegetables and whole grains) provides the background for modifying the energy balance to achieve weight loss. Extremes in intakes of carbohydrate or fats should be avoided.
        • Physical activity at any level, light, moderate or vigorous, is associated with reduced incidence of metabolic syndrome
        • Food patterns emphasizing a diet high in fruits and vegetables and whole grains is associated reduced incidence of metabolic syndrome
        • Lifestyle modification resulting in weight reduction and increased physical activity has been shown to improve risk factors associated with metabolic syndrome. Caloric restriction combined with daily activity of at least 30 minutes at moderate intensity resulted in weight loss of at least 7% and improved components of the metabolic syndrome.
      • Studies included two positive-quality cross-sectional studies (Ford et al, 2003; Irwin et al, 2002), one positive-quality systematic review/evidence report (Adult Treatment Panel III, 2002), two positive-quality cohort studies (Case et al, 2002; Lakka et al, 2003), one positive-quality case-controlled study (Pitsavos et al, 2003), one positive-quality before/after study (Katzmarzyk et al, 2003), one neutral-quality cross-sectional study (Panagiotakos et al, 2004) and two negative-quality consensus statements (Grundy, Brewer et al, 2004; Grundy, Hansen et al, 2004):
        • One positive-quality retrospective cohort study (Case et al, 2002) found weight loss obtained by calorie restriction and physical activity improved risk factors of the metabolic syndrome
        • One positive-quality before/after study (Katzmarzyk et al, 2003) of Caucasian and black men and women found an aerobic exercise training program improved risk factors of the metabolic syndrome
        • Five epidemiological studies [(four positive-quality (Ford et al, 2003; Irwin et al, 2002; Lakka et al, 2003; Pitsavos et al, 2003) and one neutral-quality (Panagiotakos et al, 2004)] support an inverse relationship between physical activity (and inactivity) and the metabolic syndrome. One study included three different ethnic groups (Irwin et al, 2002).
        • Reports of the American Heart Association, the National Heart, Lung, and Blood Institute and the American Diabetes Association (Grundy, Brewer et al, 2004; ATP III, 2002; Grundy, Hansen, et al, 2004) concluded that lifestyle modification leading to weight reduction and increased physical activity represent first-line clinical therapy for the metabolic syndrome. Nutritional therapy calls for a low intake of saturated fat, trans-fatty acids and cholesterol; reduced consumption of simple sugars; and increased fruits and vegetables and whole grains. Extremes in intakes of either carbohydrate or fats should be avoided.

      Recommendation Narrative from Hypertension

      Based on the JNC 7 report, a weight loss of as little as 10 lbs (4.5kg) reduces blood pressure and prevents hypertension in a large proportion of overweight persons.

    • Recommendation Strength Rationale

      Recommendation Strength Rationale from MNT Effectiveness

      Conclusion statement in support of the recommendation received Grade I.

      Recommendation Strength Rationale from Diabetes

      Conclusion statement from diabetes in support of the recommendation received Grade II.
      Recommendation Strength Rationale from Disorders of Lipid Metabolism
      • Research findings were across men and women of different ethnic groups residing in the United States
      • This recommendation is supported by a consensus of three organizations interested in the prevention and treatment of metabolic syndrome
      • Conclusion statements are Grade II, except conclusion statement on Dietary Pattern to Achieve Weight Loss and Reduce Components of the Metabolic Syndrome, which is a Grade IV
      • Conclusion statements were based on:
        • Two positive-quality cross-sectional studies
        • One positive-quality systematic review/evidence report
        • Two positive-quality cohort studies
        • One positive-quality case-control study
        • One positive-quality before/after study
        • One neutral-quality cross-sectional study
        • Two negative-quality consensus statements.

      Recommendation Strength Rationale from Hypertension

      The ADA Hypertension Expert Work Group concurs with the recommendations from the JNC 7 regarding weight management.

    • Minority Opinions

      Consensus reached.