The Dietary Approaches to Stop Hypertension or DASH diet promotes fruit, vegetable, and low-fat dairy food consumption while reducing saturated fat and cholesterol intake. It is recommended for the management of hypertension based on the extensive evidence of its blood pressure lowering effects, but its benefits are not limited to blood pressure.1 Evidence shows that adhering to a DASH diet leads to a reduction in body weight, body mass index (BMI), and waist circumference (WC) in comparison to a typical or usual diet.2-7 However, studies suggest that it is not significantly more effective than other healthy diets in reducing body weight.8-10
Soltani et al. conducted a systematic review and meta-analysis of 13 randomized controlled trials (RCTs) that examined the effect of the DASH diet on weight, BMI, or WC. 2 Ten studies (n=1291) found that over a period of 8 to 24 weeks, those who adhered to a DASH diet significantly decreased body weight by 1.42 kg (95% confidence interval [CI] [-2.03 – -0.82], p<0.001) compared to the control group, although the heterogeneity among the studies was high. Although weight reduction was greater in studies that examined the DASH diet with energy restriction than those without, a subgroup analysis revealed that weight loss compared to a control diet was still significant in both types of studies. Furthermore, weight reduction was significant following the DASH diet when compared to a typical diet, but was not significant when compared to other healthy diets. Lastly, weight reduction was only significant in studies among overweight and obese people (BMI >25). The patterns within these subgroup analyses were also found with regards to BMI. Over the span of 8 to 52 weeks, six studies found that BMI significantly decreased by 0.42 kg m-2 (95% CI [-0.64 – -0.20], p<0.001). Finally, two studies (n=511) with a duration of 24 weeks found that WC significantly decreased by 1.05 cm (95% CI [-1.61 – -0.24]) compared to other iso-caloric diets
Kucharska et al. conducted a recent RCT that supported these findings.4 The authors randomly assigned 131 overweight or obese patients with primary hypertension to a DASH intervention group (DIG) or a control group given only standard recommendations. Comparing baseline levels to those after three months, the authors found significant decreases in the DIG group for body mass (89.69 + 16.31 kg vs 85.60 + 15.96 kg, p=0.000), BMI (32.61 + 4.46 vs 31.11 + 4.28, p=0.000), and WC (105.30 + 11.46 cm vs 100.55 + 11.07 cm, p=0.000). Compared to the control group, which had nonsignificant changes, the DIG group had significantly bigger reductions in body mass (p=0.000), BMI (p=0.005), and WC (p=0.000).
Other studies comparing the DASH diet to another intervention support the pattern that the DASH diet may not be substantially better than alternative healthy diets.8-10 In an RCT by Appel et al., the authors randomly assigned 810 generally healthy adults with above optimal blood pressure to one of three groups for six months: Advice Only, Established, and Established + DASH.9 “Established” was a behavioral intervention that implemented traditional recommendations. After six months the mean weight change for the Advice Only, Established, and Established + DASH were respectively 1.1 kg (95% CI [-1.5 – -0.697]), 4.9 kg (95% CI [-5.6 – -4.2]), and 5.8 kg (95% CI [-6.54 – -5.06]). Although both the Established and Established + DASH interventions reduced weight significantly more than the Advice Only control, the Established + DASH intervention did not decrease weight significantly more than the Established intervention (p=0.07).
References
- Siervo M, Lara J, Chowdhury S, Ashor A, Oggioni C, Mathers JC. Effects of the Dietary Approach to Stop Hypertension (DASH) diet on cardiovascular risk factors: a systematic review and meta-analysis. Br J Nutr. 2015;113(1):1-15.
- Soltani S, Shirani F, Chitsazi MJ, Salehi-Abargouei A. The effect of dietary approaches to stop hypertension (DASH) diet on weight and body composition in adults: a systematic review and meta-analysis of randomized controlled clinical trials. Obes Rev. 2016;17(5):442-454.
- Berz JP, Singer MR, Guo X, Daniels SR, Moore LL. Use of a DASH food group score to predict excess weight gain in adolescent girls in the National Growth and Health Study. Arch Pediatr Adolesc Med. 2011;165(6):540-546.
- Kucharska A, Gajewska D, Kiedrowski M, et al.. The impact of individualised nutritional thewrapy according to DASH diet on blood pressure, body mass, and slected biochemical parameters in overweigh/obese patients with primary arterial hypertension: a prospective randomised study. Kardiol Pol 2018;76 (1):158-165.
- Chiavaroli L, Viguiliouk E, Nishi SK, et al. DASH dietary pattern and cardiometabolic outcomes: an umbrella review of systematic reviews and meta-analyses. Nutrients. 2019;11(2).
- Azadbakht L, Fard NR, Karimi M, et al. Effects of the Dietary Approaches to Stop Hypertension (DASH) eating plan on cardiovascular risks among type 2 diabetic patients: a randomized crossover clinical trial. Diabetes Care. 2011;34(1):55-57.
- Foroozanfard F, Rafiei H, Samimi M, et al. The effects of dietary approaches to stop hypertension diet on weight loss, anti-Mullerian hormone and metabolic profiles in women with polycystic ovary syndrome: A randomized clinical trial. Clin Endocrinol (Oxf). 2017;87(1):51-58.
- Jenkins DJA, Boucher BA, Ashbury FD, et al. Effect of current dietary recommendations on weight loss and cardiovascular risk factors. J Am Coll Cardiol. 2017;69(9):1103-1112.
- Appel LJ, Champagne CM, Harsha DW, et al. Effects of comprehensive lifestyle modification on blood pressure control: main results of the PREMIER clinical trial. JAMA. 2003;289(16):2083-2093.
- Azadbakht L, Mirmiran P, Esmaillzadeh A, Azizi T, Azizi F. Beneficial effects of a Dietary Approaches to Stop Hypertension eating plan on features of the metabolic syndrome. Diabetes Care. 2005;28(12):2823-2831.
- Steinberg D, Bennett GG, Svetkey L. The DASH diet, 20 years later. JAMA. 2017;317(15):1529-1530.
