You can opt for healthier food choices all you want, but if your dinner plate is towering with over-generous portions, you're probably still going to put on weight. So if you're struggling with portion control, these amusing optical illusion placemats from Japan's A.P. Works might provide some subliminal encouragement.

Through the use of clever contoured lines on a grid pattern, it looks like your cutlery and plate are actually sinking into the table, inferring that both are already incredibly heavy before you've even put food on them. The placemats also serve as an easy to way to explain Einstein's theory about space-time being like a piece of fabric that can be warped by heavier objects on it. He was referring to planets, but knives, plates, and forks get the idea across too. [A.P. Works via Spoon & Tamago]