Math was never my favorite subject. Now I’m in that stage of life, I really hate it: The reality of math tells me if I want to keep shoehorning myself into my clothes, I have to cram regular workouts into my schedule.

I’m not one of those predawn creatures who can hit the gym on their way to work. I fit in the gym on the way home at the end of the day. It works great for pounding out work-related frustration, but not so well for dinner plans. After 90 minutes of burning calories, my stomach is well past E.

Post-gym hunger gets dangerous: It’s easy to blow the 500 or 600 calories you just burned by going mouth-first into a takeout lane. Even a “30 minutes or less” recipe is going to feel 20 minutes too long. So I started stocking the freezer and refrigerator with things that take 10 minutes or less, but fill me up enough to keep me from chewing my nails until breakfast.

• Frozen oatmeal. I had my doubts the first time I unwrapped one of these hockey pucks and tossed it in the microwave. But they're actually tasty, especially if you add a pile of frozen blueberries. You can get a small box at Trader Joe's or a big box of Good Food Made Simple at Costco.

• Frozen salmon burgers. Costco is where I found my favorite lifesaver: Trident Seafoods Wild Alaskan Salmon Burgers. You can cook one in a nonstick skillet in about 6 minutes, they're juicy and they're great on an English muffin. Even better: Throw together a salad and top with a hot salmon patty.

• Tortillas. They keep longer than bread, and there's almost always something left over I can wrap in one. If I'm really desperate, cheese and mashed-up cannellini beans make the world's fastest quesadillas.

• Peanut butter yogurt. A nutritionist taught me to keep PB2, the powdered peanut butter, on hand. It's lower in calories and fat than regular peanut butter, and it's handy. Stir it into yogurt (luckily, I like plain Greek yogurt) and toss in a handful of granola, a drizzle of honey and whatever fruit is handy.

Lentil chili. Not to keep going back to Costco, but it was at one of those sampling stations on a Saturday when I discovered boxes of TastyBite Madras Lentils, a one-minute-in-the-microwave bag of lentils and red beans in a tomato sauce. I keep them at my desk for days when leaving for lunch is out of the question. For dinner, grab a bag of Trader Joe's frozen jasmine rice and top it with lentils. That makes enough to feed two people — or one very hungry me.

• Leftover soup. If you just look into the refrigerator and think "soup," it's amazing what presents itself, especially if you always keep some chicken broth and coconut milk handy. Roasted vegetables. Frozen corn and frozen hash browns. Whatever cooked meat is left from another night. Heck, just a piece of toast in the bottom of the bowl, a pile of cooked onion, some broth and some cheese will get you there.

None of this is gourmet eating, but it gets me through gym night. And if I get through enough of those, I can cook something good by the weekend. That’s my kind of math.