Answer : 4. "moderate"
Explanation :

The correct alternative to fill in the blank in the sentence "If you are the one who is planning to lose weight, remember to keep your snacking________" is:

Moderate

Solution:

"Outgoing" does not fit the context as it refers to being sociable or extroverted, which doesn't relate to snacking habits.

"Prejudiced" means having preconceived opinions that are not based on reason or experience. It's irrelevant to the context of snacking.

"Uncontrolled" implies lacking restraint or regulation, which is the opposite of what the sentence is advising.

"Moderate" is the appropriate word choice as it suggests keeping snacking within reasonable limits, which is often advised for those trying to lose weight. It implies controlling the amount and frequency of snacking to support weight loss efforts.