Is there a "best" time to grocery shop? When do you usually do your marketing? The stores are usually packed with people after work hours and on weekends too. But if that's the only window of opportunity you have, do you have any choice?

If you're tired, you may want to skip the trip altogether. We know that doing things sleepy can affect our decisions. Turns out the same is applied for grocery shopping. The reason? You're more likely to buy high-calorie foods if you are shopping in a zombie-like state, according to a study published in the journal Obesity.

Researchers from Sweden recruited 14 normal weight men to see if skimping on sleep would affect their food shopping habits. They were given $50 and were told to spend as much of it as possible while grocery shopping.

The men shopped on two occasions: once when they were sleep-deprived, and another when they had a full eight hours of rest.

The results? The men bought 9 percent more high-calorie food when they were sleep deprived and 18 percent more food when they were tired.

The lack of sleep messes your self control, and you'll be more likely to give into whatever you are craving whether it be good or bad, according to study author Christian Benedict from Uppsala University.

So if you're looking to eat a little more healthy the next round, make sure you've got enough of ZZZs before.