Like many people, when the new year started, I felt like it was time to turn over a new leaf and undo all of the damage from the gluttony of the holiday season. I was feeling sluggish and tired, and tasks that normally take me an hour or two suddenly consumed the entire day. When I got an email in January from my gym offering a two-week detox program , I reluctantly signed up. Maybe my body needed a reset?

Off limits were dairy, eggs, peanuts, lunch meats, vegetable oils, soy, coffee, black tea, soda, alcohol, sugar, gluten, artificial sweeteners, and fruit juice. These items often have harmful additives or trigger common food sensitivities that impact your physical and mental health. On the menu were most veggies, fruit, organic chicken, turkey, and pork, grass-fed beef, wild seafood, olive oil, nuts, legumes, rice, potatoes, oatmeal, almond milk, green tea, spices, herbs, and more. Many of these foods are known to aid memory and improve focus.

My husband agreed to do it with me, and the first day was easy. I swapped out my normal breakfast of scrambled eggs and coffee for steel-cut oats and green tea. I had a salad for lunch, and dinner was baked salmon, asparagus, and brown rice. Day two was pretty much the same; the food choices were easy, but I felt tired. On days three, four, and five I started to question my decision. I was exhausted, napping (something I only do when I’m sick), and heading to bed at 8:30 p.m. My 2 p.m. sugar cravings–the kind that have me rifling through my purse hoping to find an old restaurant mint–were almost unbearable. And as a result, I was probably unbearable, too.

“The food you put into your body not only affects your energy levels, but it can actually affect your emotions, too.”

But then came day six. The fog lifted, as did my mood. I felt like I had more energy than before. Mentally, my workload didn’t feel quite as heavy, and I was accomplishing more in a day than I have previously done.

That’s normal, says Megan Gilmore, author of No Excuses Detox: 100 Recipes to Help You Eat Healthy Every Day. “Serotonin, the neurotransmitter that helps regulate mood, appetite, and sleep, is mostly produced in the gut, so the food you put into your body not only affects your energy levels, but it can actually affect your emotions, too,” she says.

This was my first detox diet, and Gilmore says taking a break from certain foods is something everyone should do on a regular basis. “Our bodies encounter environmental toxins on a daily basis, including pollution, mold, heavy metals, and more,” she says. “While we don’t have much control over that, what we can do is help lighten the load placed on our crucial detox organs, like the skin, liver, and kidneys, by reducing our intake of processed foods and artificial ingredients, and eating more nutrient-rich whole foods instead.”

If your goal is to drop a couple pounds, detoxes can help with that, too. I’ll admit: my holiday free-for-all affected how my clothing fit, and my wardrobe options were becoming limited. By day four, my stomach was flat and my jeans fit again. And by day 10, I had lost six pounds.