While fruits are nutritious, some can cause discomfort or stomach upset when eaten on an empty stomach. Here are five fruits to avoid eating first thing in the morning:

1. Citrus fruits (oranges, lemons, grapefruits): High acidity can irritate the stomach lining, causing heartburn or gastritis.

2. Bananas: High natural sugars can cause a sudden spike in magnesium levels, affecting heart health and blood sugar levels.

3. Tomatoes: Acidic nature can react with digestive juices, potentially causing stomach upset or gastric ulcers.

4. Pineapple: Bromelain enzyme can irritate the stomach lining, causing nausea, indigestion, or discomfort.

5. Pears: Tough fibers can cause bloating or discomfort when eaten on an empty stomach.

To enjoy these fruits safely, consider eating them:

- After a meal
- With other foods to balance their effects
- As part of a balanced snack later in the day

Remember, everyone's digestive system is unique, so monitor your body's reactions and adjust your fruit consumption accordingly.