Inclusion Criteria:

• Aged 18 to 60 years.
• Employed by Shengli Oilfield and regularly receiving meals from a participating workplace canteen.
• Regularly eats at the participating canteen, generally on at least 4 working days per week.
• Diagnosed with primary hypertension by a qualified medical institution, or meets the diagnostic criterion of systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg on 3 measurements obtained on different days.
• Hypertension is clinically stable.
• Antihypertensive medication regimen is stable, when applicable.
• Able and willing to comply with the dietary intervention, study assessments, and follow-up procedures.
• Provides written informed consent voluntarily.

Exclusion Criteria:

• Secondary hypertension.
• Pregnancy, breastfeeding, or planning to become pregnant during the study period.
• Serious food allergy or intolerance to major foods included in the intervention diet, such as nuts, dairy products, or gluten-containing foods.
• Major cardiovascular or cerebrovascular event within the previous 6 months, such as myocardial infarction or stroke.
• Severe cardiopulmonary disease, such as heart failure or severe asthma.
• Cancer, advanced kidney disease, severe liver disease, or another serious medical condition.
• A medical condition requiring a specialized therapeutic diet that would interfere with the study intervention.
• Severe psychiatric illness.
• Severe cognitive impairment that prevents understanding of the informed consent form or compliance with study procedures.
• Hearing impairment or physical disability that would substantially interfere with participation.
• Any other condition that, in the judgment of the research team, makes the individual unsuitable for participation.