The No. 1 fear of college students isn’t doing the walk of shame after a night of beer bongs and body shots. No, the real fear is the dreaded freshman 15.

College can be one of the most amazing, invigorating and freeing times in life. No one wants to ruin four years of fun by getting fat!

The good news? The freshman 15 is totally avoidable. Not by starving yourself. Not by taking stupid laxatives. Not by going on some dumb “all liquid” diet. It’s actually pretty simple: All you need to do is stop eating crap.

Meat: The dead, rotting, decomposing flesh of a carcass – n-a-s-t-y. Chicken, burgers and bacon are full of pesticides, steroids and antibiotics – not to mention a ton of cholesterol and fat.

The Skinny Alternative: There are countless meat-free substitutes that have the same taste and texture of meat, sans the cholesterol, high-fat content and other nastiness. Products like Boca “chicken” cutlets and vegan BBQ “riblets” can be found in every major grocery store, and most dining halls are bulking up their meat-free options in order to meet the growing demand.

Dairy: Got pus? Milk does. It’s also been linked to acne, allergies, asthma, cancer, diabetes, heart disease, obesity and a slew of other things you don’t want anything to do with. We are the only species on Earth that drink milk as adults. And we’re the only species on the planet that drinks the milk of another species. Would you breastfeed from your mom at this age? No! So why would you breastfeed from a calf’s mom? Gross! Worried about calcium?

Here’s the dirty secret that the dairy industry doesn’t want you to know. Researchers from Harvard, Yale, Penn State and the National Institutes of Health all studied the effects of dairy-product intake on bone health. Not one of them found dairy foods to be a deterrent for osteoporosis!

The Skinny Alternative: Um, hello? Ever heard of soy milk, rice milk, hempseed milk, oat milk, or almond milk? Get with the millennium. Not only are these alternatives guaranteed to be pus-free, they’re also often fortified with calcium and vitamin D. Eggs: Eggs are chicken periods. Think about it. If that doesn’t make you puke up your omelet, how about this: Many grocery-store eggs are infected with salmonella – bacteria that will give you diarrhea for days. Diarrhea in a dorm bathroom? No, thanks! P.S. A single egg has as much cholesterol as three servings of beef tenderloin.

The Skinny Alternative: Replace your morning chicken period with scrambled tofu. And for baking cookies, brownies, or cupcakes, replace the eggs with bananas, applesauce, or commercial egg replacers like Ener-G. The possibilities are endless. Soda: There is nothing in soda, either diet or regular, that’s good for you! But it’s like crack for so many and people are downing it by the bucket. Ditch this liquid Satan and see the difference it makes.

The Skinny Alternative: Um, ever hear of water? Drink it! It’s vital for flushing toxins, staying hydrated and eliminating garbage from your body.

The choice is yours: Four years of fun with good health, good skin and a hot bod or the dreaded and inevitable freshman 15. You decide. Need help getting started Check out peta2.com/SkinnyBitch, where you can get the skinny on what to eat, how to get more vegetarian options in your dining hall and dirt on the industries that sell you crap. Need a further kick in the ass? Check out “Skinny Bitch” and “Skinny Bitch in the Kitch.”

Rory Freedman is the co-author of New York Times’ best-selling books “Skinny Bitch” and Skinny Bitch in the Kitch,” and her newest release, “Skinny Bitch: Bun in the Oven.”