Ramadan Fasting is Safe for Healthy Adults
Ramadan fasting is safe and without adverse health impact in healthy adults without chronic medical conditions, and may even provide metabolic benefits including improved lipid profiles and reduced inflammation. 1
Evidence Supporting Safety in Healthy Individuals
Metabolic and Cardiovascular Benefits
Ramadan fasting produces significant increases in HDL cholesterol and reductions in LDL cholesterol, particularly in metabolically unhealthy individuals, with time-restricted feeding resulting in small but significant reductions in total cholesterol and LDL cholesterol. 2
Serum triglycerides decrease by 16-42% across various studies, accompanied by decreased diastolic blood pressure in individuals who fast during Ramadan. 2
Healthy adults experience reductions in body weight, waist circumference, body mass index, body fat, blood glucose, and both systolic and diastolic blood pressure during Ramadan fasting. 3
Hematologic and Immune System Effects
Ramadan fasting increases red blood cells, white blood cells, and platelet counts while decreasing blood cholesterol, triglycerides, LDL cholesterol, and VLDL cholesterol. 3
The immune system changes during Ramadan fasting are mild and transient, returning to baseline pre-Ramadan status shortly afterward, with no adverse immunologic consequences in healthy individuals. 4
Ramadan fasting decreases inflammation markers including pro-inflammatory cytokines IL-1β, IL-6, tumor necrosis factor α, and cancer promotion factors. 3
Physiological Adaptations
During fasting periods extending beyond several hours, healthy individuals develop physiological ketosis with ketone levels typically ranging from 0.3 to 4 mmol/L, characterized by normal pH, normal blood glucose, and serum bicarbonate usually not lower than 18 mEq/L—this is a normal metabolic adaptation, not a pathological state. 5
As glycogen stores deplete, low insulin levels trigger fatty acid release from adipocytes, with oxidation generating ketones that serve as alternative fuel for skeletal muscle, cardiac muscle, liver, kidney, and adipose tissue, sparing glucose for the brain and erythrocytes. 5
Organ System Safety Profile
Among healthy adults, there are no adverse effects of Ramadan fasting on the brain, heart, lung, liver, kidney, hematologic profile, endocrine function, or cognitive functions. 3
No adverse effects on respiratory and cardiovascular systems have been documented in healthy individuals observing Ramadan fasting. 6
Neuropsychiatric functions remain intact, with studies showing reduced anxiety levels during Ramadan fasting. 3
Important Caveats for Healthy Individuals
Hydration and Lifestyle Considerations
While healthy individuals tolerate Ramadan fasting well, some studies have reported signs of dehydration and raised serum concentrations of uric acid during fasting periods, though these changes are unlikely to have significant effects on healthy individuals. 7
The duration of daily fasting varies from 12 to 18 hours depending on geographical location and season, with longer durations in regions close to the poles. 1
Pregnancy Considerations
- Ramadan fasting during the second trimester of pregnancy has been shown to be safe and does not result in negative fetal outcomes or maternal oxidative status alterations. 4
Populations Who Should NOT Fast
Despite safety in healthy individuals, the following groups should avoid Ramadan fasting:
Patients with acute coronary syndrome, advanced heart failure, recent percutaneous coronary intervention or cardiac surgery, and severe aortic stenosis or poorly controlled arrhythmias. 2
Patients with acute hepatitis, Child B and C cirrhosis, and peptic ulcer disease. 1
Type 1 diabetics and poorly controlled type 2 diabetics due to threefold increased risk of severe hyperglycemia with or without ketoacidosis. 1, 5
Practical Recommendations for Healthy Adults
Healthy adults can safely observe Ramadan fasting without medical supervision or special precautions. 1
The beneficial effects on lipid profiles are most pronounced when Ramadan fasting is accompanied by weight loss exceeding 5% of body weight. 2
Maintain adequate hydration during non-fasting hours (between sunset and dawn) to prevent dehydration-related complications. 7
Consume two balanced meals—Iftar (after sunset) and Suhur (before dawn)—to maintain nutritional adequacy. 1