suggested that

yes the sentence is correct. The problem is that the simple past tense and the subjunctive are the same in modern English. Here you are using the subjunctive which in old English was "aet"

Some would sy that the present subjunctive is correct here:

My friend suggested that she eat high-fibre cereals at night to lose weight.

Thank you, mjcbrown and fivejedjon. I really appreciate your helpful response.

Between "eat" and "ate" after the verb "suggested" in this kind of sentence, which do you think is the more natural to use? and more commonly used?

These are all correct.

My friend suggested that she ate high-fibre cereals at night to lose weight. (past subjunctive)

My friend suggested that she ate high-fibre cereals at night to lose weight. (past indicative--simple past; BrE)

My friend suggested that she eat high-fibre cereals at night to lose weight.(pres

Thank you, Ivanhr, for your input.

Would you, please explain the difference in meaning between the four sentences?
If there is significant difference in meaning between them, can they be used interchangeably?
Which of the 4 sentences is more natural and common?

AnonymousBetween "eat" and "ate" after the verb "suggested" in this kind of sentence, which do you think is the more natural to use? and more commonly used?

The present subjunctive version is probably the most common. In BrE, the version with "should" is also relatively common.

IvanhrThe present subjunctive version is probably the most common.

In AmE perhaps. Not in BrE, in my opinion.

Ivanhr In BrE, the version with "should" is also relatively common.

Yes.