Another week, another freak out about some random thing making you fat. (Last week it was shampoo.) Today in crazy/fat headlines we give you…credit cards!Over at Time there’s an article about a new study showing that paying with plastic instead of cash might make you buy more junk food. How? Paying with credit or debit cards lowers your impulse control (which is why people are so much more likely to buy crazy, overpriced stuff when they pay with a card), whereas paying with cash forces you to think about it more.Junk food is often an impulse buy, and when you aren’t mindful of your purchases, you’re way more likely to toss a supersize bag of Cheetos and a six-pack of Yoo-hoo (yuck!) into your shopping cart.Freak out factor: MediumSure, there are loads of other reasons why people gain weight, but there’s really some truth to this. (Dang!) Mindfulness is super important for healthy eating because if you’re just coasting along not paying attention, most likely you’ll be reaching for the not-so-healthy stuff.QUIZ: What’s Driving Your Eating Behavior?And although we can’t blame the rise in obesity on credit cards, it is interesting to note that the use of cash is declining so rapidly that in the last fiscal year the U.S. Treasury stopped producing $10 bills for the first time in 30 years.Just connecting the dots here.Sure, credit and debit cards are great for their convenience factor, but if you’re trying to eat healthier, it wouldn’t hurt to bring out the Benjamins (or, er…Lincolns).MORE: Is Money Affecting Your Relationships?