Losing weight can lower blood pressure in people who are overweight or obese.1,2 Excess weight is one of the most preventable risk factors for high blood pressure and its related diseases.1,2
Weight Loss Recommendations
In the 2016 guidelines for medical care of patients with obesity, experts recommend that overweight or obese people with elevated blood pressure or hypertension should lower their weight by 5% to 15% or more of their body weight.3 They should use lifestyle modifications which include regular physical activity and a restricted-calorie diet to achieve their blood pressure goals [Recommendation Grade A; BEL 1]. Some of these people may need to add weight loss medication, such as orlistat or lorcaserin, to their lifestyle therapy to achieve their weight loss goals [Recommendation Grade B; BEL 1]. People with a BMI ≥35 and one or more severe complications related to obesity may need to consider bariatric surgery to lower weight and improve CVD risk [Recommendation Grade A; BEL 1].
The 2017 American College of Cardiology (ACC) and American Heart Association (AHA) hypertension guidelines state that doctors should promote nonpharmacological therapy to everyone with elevated blood pressure or diagnosed hypertension.1 Weight loss is specifically recommended for adults with elevated or high blood pressure who are overweight or obese [Strong Recommendation (Level A)]. They recommend most overweight adults should aim to lower body weight by at least 1 kg. People can expect about 1 mm Hg reduction of systolic blood pressure for every 1 kg of weight loss.
The 2013 Obesity Expert Panel review2 led to the release of the 2013 ACC/AHA guidelines4 on the management of overweight and obesity in adults. They recommend that doctors counsel overweight and obese adults that they may be at increased risk for cardiovascular disease, type 2 diabetes, and all-cause mortality.2,4 People should also be told that their risk of these serious conditions, such as fatal coronary heart disease, increases as their BMI increases. Sustained weight loss of more than 5% of body weight can lower blood pressure, lower LDL cholesterol, raise HDL cholesterol levels, and reduce the need for antihypertensive medications.4 This statement is based on the review of eight systematic reviews and meta-analyses which included randomized trials of both dietary interventions alone and dietary plus orlistat (weight-loss medication) interventions. The authors determined that the weighted mean reduction in blood pressure from a 5% weight loss was about 3 mm Hg systolic and 2 mm Hg diastolic. They concluded that even a modest sustained weight loss of 3% to 5% of body weight can have significant health benefits.
Studies of Efficacy of Weight Loss for Blood Pressure Reduction
Studies show that weight loss can lower blood pressure in overweight and obese adults. A 2016 Cochrane Review meta-analysis found 8 randomized controlled trials including a total of 2,100 adults (mean age 45 to 66 years) which studied weight-reducing diets against no dietary intervention for at least 24 weeks.5 The review found that people on the dietary regimen lost more weight than the controls by a mean difference (MD) of -4.0 kg (95% CI [-4.8 – -3.2]). Only three of the studies measured blood pressure in relation to weight loss so although there is evidence to support the premise that lowering weight lowers blood pressure, the small sample size involved resulted in it being rated as low-quality evidence by the authors. The analysis of the three studies found that blood pressure was reduced in people on the weight loss diets compared to controls by MD -4.5 mm Hg (95% CI [-7.2 – -1.8 mm Hg]) for systolic blood pressure and MD -3.2 mm Hg (95% CI [-4.8 – -1.5 mm Hg]) for diastolic blood pressure.
A 2016 systematic review and meta-analysis of 24 randomized controlled trials of six-month duration or longer (n=23,858 overweight or obese adults, age 34 – 67 years) evaluated the effect of a variety of dietary interventions and their estimated aggregate effects on blood pressure.6 An analysis of studies grouped by similar diets found that the DASH diet (four trials, five comparison groups) resulted in the largest reduction in blood pressure with −7.62 mm Hg (95% CI [-9.95 – -5.29]) for systolic and −4.22 mm Hg (95% CI [-5.87 – -2.57]) for diastolic. Next most beneficial diets were a low-calorie diet with blood pressure reductions of -3.18 mm Hg (95% CI [-4.24 – -2.11]) systolic and -1.28 mm Hg (95% CI [-1.87 – -0.69]) diastolic and a low sodium, high potassium diet with a -3.14 mm Hg (95% CI [-6.27 – -0.02]) systolic and -2.01 mm Hg (95% CI [-3.40 – -0.62]) diastolic. A low sodium diet resulted in blood pressure reductions of −2.06 mm Hg (95% CI [-3.50 – -0.63]) for systolic and −1.30 mm Hg (95% CI [-2.37 – -0.23]) for diastolic. Ten of the trials included only hypertensive participants (≥140/80) and these participants had significantly greater net blood pressure reductions than the trials of normotensive people.
A 2003 meta-analysis of 25 randomized controlled trials of nonpharmacologic weight loss (n=4,874, mean initial BMI 30.7 kg/m2) found that each kilogram of weight loss resulted in blood pressure reductions of -1.05 mm Hg (95% CI [-1.43 – -0.66) systolic and -0.92 mm Hg (95% CI [-1.28 – -0.55) diastolic.7 They also found that in populations with more than 5 kg weight loss as compared to less than 5 kg weight loss, the blood pressure reduction was significantly more with -6.63 mm Hg (95% CI [-8.43 – -4.82]) vs -2.70 mm Hg (95% CI [-4.59 – -0.81]) systolic and -5.12 mm Hg (95% CI [-6.48 – -3.75]) vs -2.01 mm Hg (95% CI [-3.47 – -0.54]) diastolic.
Health Risks of Overweight and Obesity
Overweight and obesity raise the risk of many serious health conditions.2,3,8-16 Obese adults have at least a 20% higher risk of death than normal weight adults from cardiovascular disease and all other causes.9 Disease and health conditions associated with overweight and obesity include:2,3,8-16
- Cholesterol problems, such as high LDL cholesterol, high triglycerides, and low HDL cholesterol
- Type 2 diabetes (T2DM)
- Cardiovascular disease (CVD) such as atherosclerosis, heart attack, stroke, and heart failure
- Nonalcoholic fatty liver disease
- Obstructive sleep apnea
- Acid reflux disease
- Some types of cancer such as breast, uterine, colon, kidney, gallbladder, and liver
- Polycystic ovary syndrome
- Female infertility
- Male hypogonadism (low testosterone)
- Alzheimer’s disease and dementia
- Mental health problems such as depression and anxiety
- Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension 2017.
- Expert panel report: guidelines (2013) for the management of overweight and obesity in adults. Obesity (Silver Spring) 2014; 22 Suppl 2: S41-410.
- Garvey WT, Mechanick JI, Brett EM, et al. American Association of Clinical Endocrinologists and American College of Endocrinology comprehensive clinical practice guidelines for medical care of patients with obesity. Endocr Pract 2016; 22 Suppl 3: 1-203.
- Executive summary: Guidelines (2013) for the management of overweight and obesity in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Obesity Society published by the Obesity Society and American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Based on a systematic review from the The Obesity Expert Panel, 2013. Obesity (Silver Spring) 2014; 22 Suppl 2: S5-39.
- Semlitsch T, Jeitler K, Berghold A, et al. Long-term effects of weight-reducing diets in people with hypertension. Cochrane Database Syst Rev 2016; 3: Cd008274.
- Gay HC, Rao SG, Vaccarino V, Ali MK. Effects of different dietary interventions on blood pressure: systematic review and meta-analysis of randomized controlled trials. Hypertension 2016; 67 (4): 733-739.
- Neter JE, Stam BE, Kok FJ, Grobbee DE, Geleijnse JM. Influence of weight reduction on blood pressure: a meta-analysis of randomized controlled trials. Hypertension 2003; 42 (5): 878-884.
- Benjamin EJ, Virani SS, Callaway CW, et al. Heart disease and stroke statistics - 2018 update: a report from the American Heart Association. Circulation 2018; 137 (12): e67-e492.
- Borrell LN, Samuel L. Body mass index categories and mortality risk in US adults: the effect of overweight and obesity on advancing death. Am J Public Health 2014; 104 (3): 512-519.
- Danaei G, Ding EL, Mozaffarian D, et al. The preventable causes of death in the United States: comparative risk assessment of dietary, lifestyle, and metabolic risk factors. PLoS Med 2009; 6 (4): e1000058.
- Bhaskaran K, Douglas I, Forbes H, dos-Santos-Silva I, Leon DA, Smeeth L. Body-mass index and risk of 22 specific cancers: a population-based cohort study of 5.24 million UK adults. Lancet 2014; 384 (9945): 755-765.
- Guh DP, Zhang W, Bansback N, Amarsi Z, Birmingham CL, Anis AH. The incidence of co-morbidities related to obesity and overweight: a systematic review and meta-analysis. BMC Public Health 2009; 9: 88.
- Luppino FS, de Wit LM, Bouvy PF, et al. Overweight, obesity, and depression: a systematic review and meta-analysis of longitudinal studies. Arch Gen Psychiatry 2010; 67 (3): 220-229.
- Kodama S, Horikawa C, Fujihara K, et al. Quantitative relationship between body weight gain in adulthood and incident type 2 diabetes: a meta-analysis. Obes Rev 2014; 15 (3): 202-214.
- Strazzullo P, D'Elia L, Cairella G, Garbagnati F, Cappuccio FP, Scalfi L. Excess body weight and incidence of stroke: meta-analysis of prospective studies with 2 million participants. Stroke 2010; 41 (5): e418-426.
- Albanese E, Launer LJ, Egger M, et al. Body mass index in midlife and dementia: systematic review and meta-regression analysis of 589,649 men and women followed in longitudinal studies. Alzheimers Dement (Amst) 2017; 8: 165-178.