Yogurt, a popular fermented food, is loved for its palatable taste and high nutritional value. It provides protein, calcium, zinc, B vitamins, and probiotics.

Doctor Nguyen Thi Phuong from the Department of Nutrition at Tam Anh General Hospital in Hanoi, says that thanks to billions of live probiotics, yogurt helps balance the gut microbiome, inhibits harmful bacteria, and supports digestion and nutrient absorption. However, eating yogurt on an empty stomach can affect the effectiveness of these probiotics and cause digestive upset in those with sensitive stomachs.

The survival and effectiveness of probiotics in yogurt depend on the acidity levels in the stomach and intestines. On an empty stomach, gastric juices have a low pH (around 1-3), a strongly acidic environment. This environment helps digest food and eliminate harmful bacteria, but it's also a major obstacle for yogurt's probiotics.

Probiotics like lactobacillus and bifidobacterium are relatively sensitive to acid. When yogurt is consumed on an empty stomach, most of these strains are destroyed before they reach the small and large intestines where they offer benefits such as aiding digestion, synthesizing vitamins, and regulating immunity. Only after eating some food, when stomach acid levels decrease (to around pH 4-5), can probiotics easily pass through to the intestines and take effect.

Eating very cold or tart yogurt on an empty stomach can cause stomach discomfort, heartburn, mild nausea, or stomach cramps in sensitive individuals. Doctor Phuong advises people with a history of stomach ulcers, acid reflux, hyperacidity, or acute gastritis not to eat yogurt on an empty stomach. The acid in yogurt, combined with high levels of gastric juices, can irritate the stomach lining, leading to increased pain and discomfort. People experiencing digestive issues or diarrhea, whose gut microbiome is disrupted and unstable, should also avoid yogurt on an empty stomach as it can worsen symptoms. The elderly, those with weak digestive systems, or children under the age of two should also limit yogurt consumption at this time, especially if it's cold.

The stomachs of healthy individuals can regulate pH quite quickly when food, including yogurt, is ingested. Therefore, yogurt can provide nutrients and benefit the gut of those with healthy digestive systems, even when eaten cold.

Plain yogurt combined with oatmeal and chia seeds enhances flavor and adds nutritional value. Photo: Hue Ho

To maximize benefits, it's recommended to eat yogurt 30 minutes to two hours after a main meal. By then, the stomach has food, and the pH level has been adjusted, creating favorable conditions for probiotics to survive and travel to the small and then the large intestine to exert their effects. Eating yogurt in the late afternoon or after exercise is also suitable, as it replenishes protein, restores energy, and supports the digestive system.

Regular yogurt consumption helps reduce the risk of digestive disorders, bloating, constipation, and strengthens immunity against pathogens from food and the environment. Adults should consume about 1-2 cups of yogurt (100-300 g) daily for beneficial probiotics, calcium, and protein. Consuming too much yogurt, over 400 g per day, can lead to bloating, digestive upset, excess calories, and weight gain, especially with sweetened varieties.

Doctor Phuong recommends choosing plain or low-sugar yogurt to control blood sugar and weight. Combining it with soluble fiber-rich foods like oatmeal, chia seeds, or fresh fruit adds natural sweetness and fiber, slows digestion, and promotes a feeling of fullness.

Ly Nguyen