My husband uses it because he eats many of the same things as I do and he is not inclined to spend the time to search each food - or especially to recreate my recipes (because we can't share). I do the research and log it properly and then he just asks how many calories and adds it to his diary. It is a quicker way for him to account for his own calories. I rarely use it on my diary. I probably have done it once or twice.
