How Effective Are Dietitians in Weight Management? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract

Effective, evidence-based strategies to prevent and treat obesity are urgently required. Dietitians have provided individualized weight management counselling for decades, yet evidence of the effectiveness of this intervention has never been synthesized. The aim of this study was to examine the effectiveness of individualized nutrition care for weight management provided by dietitians to adults in comparison to minimal or no intervention. Databases (Cochrane, CINAHL plus, MedLine ovid, ProQuest family health, PubMed, Scopus) were searched for terms analogous with patient, dietetics and consultation with no date restrictions. The search yielded 5796 unique articles, with 14 randomized controlled trials meeting inclusion criteria. The risk of bias for the included studies ranged from unclear to high. Six studies found a significant intervention effect for the dietitian consultation, and a further four found significant positive change for both the intervention and control groups. Data were synthesized through random effects meta-analysis from five studies (n = 1598) with weight loss as the outcome, and from four studies (n = 1224) with Body Mass Index (BMI) decrease as the outcome. Groups receiving the dietitian intervention lost an additional 1.03 kg (95% CI:−1.40; −0.66, p < 0.0001) of weight and 0.43 kg/m2 (95% CI:−0.59, −0.26; p < 0.0001) of BMI than those receiving usual care. Heterogeneity was low for both weight loss and BMI, with the pooled means varying from 1.26 to −0.93 kg and −0.4 kg/m2 for weight and BMI, respectively, with the removal of single studies. This study is the first to synthesize evidence on the effectiveness of individualized nutrition care delivered by a dietitian. Well-controlled studies that include cost-effectiveness measures are needed to strengthen the evidence base.

Anthropometric and blood pressure changes in patients with or without nutritional counselling during cardiac rehabilitation: a retrospective study

“…OR, odds ratio; 95% CI, 95% confidence interval; SBP, systolic blood pressure. A meta-analysis that evaluated the effect of a dietitian in traditional weight management interventions reported an additional weight loss of 1.0 kg (0.4 kg m À2 ), which aligns with our findings in CR patients (26) . Most of the studies evaluating traditional weight management in obese patients reported a short-term weight loss between 1.6 and 2.5 kg after the intervention (6-12 months).…”

Exploring the highs and lows of very low carbohydrate high fat diets on weight loss and diabetes‐ and cardiovascular disease‐related risk markers: A systematic review

“…Appropriateness of the diet regimen should be considered prior to nutritional management. Referral to a dietitian for individualised medical nutrition therapy 56 and monitoring is recommended to promote adherence and manage nutrition‐ and disease‐related risks of restricted dietary regimens. SFA should be monitored to ensure intakes are within recommended ranges and for people with diabetes the risk of hypoglycaemia should be considered.…”

Maintaining the Outcomes of a Successful Weight Gain Prevention Intervention in Mid-Age Women: Two Year Results from the 40-Something Randomized Control Trial

“…The 40-Something study findings illustrate the potential benefits of extending this model to application in the prevention of obesity, particularly abdominal obesity, and thus chronic disease at high risk life stages such as menopause, to prevent chronic disease rather than treating a person for chronic disease once it has developed. Other researchers have suggested that motivational interviewing be used in the primary care setting for weight loss [33], and a recent systematic review has shown dietitians to be more effective than other interventions within the primary care setting in achieving weight control [34]. Further intervention studies are needed with this relatively overlooked target group to examine the effectiveness, including cost-effectiveness, of weight gain prevention interventions to support healthy ageing.…”