using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		var s = "CATEGORY:    SIDES   DATE CREATED:   03/12/16"; //PRODUCT:      CARROTS    DATE DELETED:    05/11/17";
		var rx = @"(\b(?:CATEGORY|PRODUCT|DATE (?:CREA|DELE)TED):)";
		var chunks = Regex.Split(s, rx);
		Console.WriteLine(string.Concat(chunks.Select(x => Regex.IsMatch(x, $"^{rx}$") ? x : new String(' ', x.Length))));
		var delim = @"\b(?:CATEGORY|PRODUCT|DATE (?:CREA|DELE)TED):";
		Console.WriteLine(Regex.Replace(s, $@"(\G(?!^)\s*|{delim}\s*)(?!{delim})\S", "$1 "));
	}
}

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