People with obesity and high blood pressure who start the protein-sparing modified fast see a slightly greater drop in their diastolic (bottom number) blood pressure in the first year than those on other diets, but after that, the benefit disappears.
Evidence from Studies
No evidence studies found yet.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Whether PSMF leads to greater and sustained reductions in diastolic blood pressure compared to other diets in adults with obesity and hypertension across multiple trials.
A systematic review and meta-analysis of RCTs comparing PSMF to other diets in adults with BMI ≥30 and systolic BP ≥140 mmHg, reporting diastolic BP change at 6, 12, and 60 months. Primary outcome: mean difference in diastolic BP change at 1 and 5 years.
Whether random assignment to PSMF causes greater and sustained reductions in diastolic blood pressure compared to other diets in obese hypertensive adults.
A multicenter RCT with 300+ adults aged 40–70, BMI ≥30, and systolic BP ≥140 mmHg, randomized to PSMF (800 kcal, 1.2–1.5g protein/kg/day) or a matched calorie-restricted balanced diet, with monthly BP measurements for 5 years. Primary outcome: change in diastolic BP at 1 and 5 years.
Whether initiating PSMF is associated with greater diastolic BP reduction at one year compared to other diets in obese hypertensive adults after adjusting for confounders.
A prospective cohort of 1000+ obese adults with hypertension initiating any diet, with BP measured at baseline and annually for 5 years. Multivariable regression adjusts for age, sex, race, baseline BP, medications, and BMI to estimate association between PSMF initiation and diastolic BP change.
Whether individuals with ≥5 mmHg diastolic BP reduction at one year are more likely to have initiated PSMF than those with <2 mmHg reduction.
A case-control study comparing 200 adults with ≥5 mmHg diastolic BP reduction at year one with 200 controls with <2 mmHg reduction. Exposure (PSMF initiation) is confirmed via medical records. Odds ratios are calculated after matching for age, sex, baseline BP, and medications.
Whether current diastolic blood pressure correlates with past PSMF use in a population sample, without establishing timing or causality.
A cross-sectional survey of 2000 adults with obesity and hypertension asking whether they ever tried PSMF and measuring current diastolic BP. Analysis examines association between past PSMF use and current BP, adjusting for age and medications.