The food industry is always singing the praises of some new “superfood.” Pomegranates, blueberries, dark chocolate, acai…it’s endless and it drives me nuts. I wrote a column about health for ten years, and if there’s one thing you learn when you spend a lot of time looking into this stuff, it’s that it’s all bunk. There is no such thing as a “superfood.”

That being said, when 3 p.m. rolls around, and you head over to the vending machine to grab a bag of chips and a cola, you know that’s a terrible idea, right?

While no food is going to make you immortal and all knowing, what you eat does have both long-term and immediate effects on brain function and memory – and, as a result, your job performance. Studies suggest that obesity is associated with decline in mental function, but you don’t necessarily need to put on a lot of weight to feel the effects.

One food that makes you stupid? Sugar.

Look, I’m not on the currently trendy “sugar is death” train but I do think people probably eat way too much of it. Cookies, sweets, soda, even savoury snacks like chips, they all contain sugar. The worst culprit, according to scientists, is high fructose corn syrup. That stuff is in pretty much all packaged foods. And eating a lot of it may affect your brain function in as little as six weeks.

Also, all carbs are sugar. If you’re going to eat them stay away from white flour and stick to whole grains like quinoa and brown rice. (I’m also not on the anti-gluten bandwagon and am hoping people get over that one soon.) And eat fruit.

Stay away from junk and your brain will thank you.

And drink water. Research shows that even mild dehydration can influence mood, energy levels and your ability to think clearly. Make sure you always have water on hand so you don’t forget.

Now, if you’re looking for something to snack on at work, try these things instead of the usual.

Hard boiled egg. Egg yolks are a great source of choline, an essential nutrient necessary for brain function and development. Eggs are also rich in protein. And that whole “Eggs are high in cholesterol, cholesterol is bad for you” thing is turning out to have been rather exaggerated. Eggs are great. I’m suggesting hard boiled because it’s probably easier to bring a hard boiled egg to work than to scramble one at your desk.

Peanut butter. Peanut butter is also, high in choline – though much lower than eggs – and protein, and it’s a good source of Vitamin E, the lack of which has been associated with cognitive decline. Almond and Walnut butter are also good choices.

Spinach. Leafy greens such as spinach, kale, and collards have been associated with slowing cognitive decline. Researchers in one study found that people in their 80s who ate one to two servings per day had the cognitive ability of a person 11 years younger than those who ate none. They “found that vitamin K, lutein, folate and beta-carotene were most likely helping to keep the brain healthy.”

Berries. Berries, which are high in flavonoids – a form of antioxidant – have been associated with keeping memory and brain function sharp, as well as protecting against health problems such as cancer and stroke.

Salmon. Fatty fish such as salmon is high in Omega 3 fatty acids, which you absolutely need for the smarts to function properly. The Omegas 3, 6, and 9, have to be consumed in balance in order to work, and most of us actually get enough of the other two, and even too much of the sixes. But we tend lack the threes. Salmon also contains DHA which is essential for synaptic function. Don’t take fish oil supplements though. They probably don’t work. (But be mindful of eating fish at your desk. Your coworkers might hate the smell.)