The documentary "Super Size Me" follows Morgan Spurlock as he eats only McDonald's food for 30 days. While there were some guidelines, it wasn't exactly a strict "experiment" with specific rules. However, here are the 4 main guidelines that Morgan followed:

1. Eat three meals a day at McDonald's: This was the most important rule. He could only eat food from McDonald's, and he had to consume three meals a day.

2. Eat everything on the menu at least once: Morgan wasn't allowed to skip any items on the McDonald's menu, so he had to try everything at least once.

3. Super Size when offered: If he was offered a Super Size option, he had to take it. This is where the "Super Size Me" title comes from.

4. No exercise: To isolate the impact of the McDonald's diet, Morgan wasn't allowed to exercise during the 30 days.

These were the main guidelines Morgan followed during the film. It's important to note that it wasn't a strictly controlled scientific experiment, but rather a personal journey to showcase the potential negative effects of fast food consumption.