Get specific Sharepoint fields using FieldValuesAsText CSOM C#

Question

When using the FieldValuesAsText option, it returns all the data of 120 columns of text. I only need about 4 columns. I did try putting the columns I wanted with the FieldValuesAsText option. It did return the 4 fields I wanted, but the FieldValuesAsText area still returned 120 columns.

var listItem = list.GetItemById(itemId);
var FieldValues = listItem.FieldValuesAsText;
clientContext.Load(FieldValues);
clientContext.ExecuteQuery();

Does anybody know a way to limit the number of columns returned using the FieldValuesAsText option?