When should watermelon not be eaten?

Generally, people should avoid eating watermelon under the following circumstances: improper timing or food combinations, pregnant women and women during menstruation, individuals with weak gastrointestinal function, diabetic patients with poor blood glucose control, and patients with renal failure. The specific reasons are as follows:

1. Improper Timing and Food Combinations

Eating watermelon immediately after a meal may dilute gastric juices, impairing digestion and nutrient absorption. Additionally, avoid drinking milk or consuming calcium-rich foods right after eating watermelon, as the sugars in watermelon may combine with oxalic acid and calcium ions to form insoluble precipitates, which can interfere with calcium absorption.

2. Pregnant Women and Women During Menstruation

Excessive consumption of watermelon by pregnant women may increase the risk of gestational diabetes. Watermelon is considered cooling in nature, and since postpartum women and those menstruating often have weakened constitutions, consuming watermelon may lead to physical discomfort.

3. Individuals with Weak Gastrointestinal Function

Watermelon contains high amounts of water and fiber. Overconsumption may increase the burden on the digestive system, leading to bloating, diarrhea, and other gastrointestinal discomforts. Eating watermelon on an empty stomach may also stimulate gastric acid secretion, worsening stomach discomfort.

4. Diabetic Patients with Poor Blood Glucose Control

Watermelon has a relatively high sugar content. For diabetic patients whose blood glucose levels are poorly controlled, consuming watermelon may cause significant fluctuations in blood sugar, potentially triggering acute diabetic complications such as diabetic ketoacidosis or hyperosmolar hyperglycemic state.

5. Patients with Renal Failure

Patients with kidney failure often have reduced urine output and are prone to hyperkalemia (high potassium levels). Since watermelon is rich in potassium, consuming it may exacerbate hyperkalemia, potentially leading to life-threatening arrhythmias.

When consuming watermelon, individuals should consider their personal health conditions and body constitution to determine whether it is appropriate for them, and follow proper guidelines regarding timing and method of consumption.