You could lose hours wandering around Trader Joe's, Kroger, and Wegmans, going up and down every aisle. You also drastically up your odds of nabbing excess food you don't really need (i.e. a lot of junk).

Three-time best-selling author Candice Kumai explains how to make your time in the grocery store quick and effective, as well as what to look for—and what to leave on the shelf.

1. Go in with a list

The smartest, fittest, and most efficient shoppers plan the week’s meals in advance and make a list before hitting the aisles. It will ensure accuracy (“Dammit, I forgot eggs!”), save time, and help you resist tempting treats.

2. Shop the perimeter of the store first

In Defense of Food, a memorable book by Michael Pollan, taught me years ago to shop the outermost areas of the supermarket first. These shelves are full of the most important food staples, like fruit, vegetables, eggs, yogurt, butter, and lean protein, and often bulk bins of whole grains.

20 Fittest Foods for Men
20 Fittest Foods for Men

3. Look past label lingo

Not sure what makes low-fat different from light? Don’t fret. “All things in moderation” still reigns as the rule of thumb here, so prioritize clean eating over a quest for guilt-reducing vocabulary. For example, go for all-fruit spreads and natural nut butter. Ask yourself: Could Grandma have bought this product when she was my age? If the answer is yes, you have permission to put it in your cart.

4. Identify each ingredient

Less is definitely more. Look for a short list of natural ingredients (organic is even better), and if you can’t pronounce what’s in it, don’t buy it. Mystery ingredients are usually added for taste, appearance, or to preserve freshness. When fat (oils), sugar (corn syrup, fructose, anything ending in “ose”), or salt are at the top of the ingredients list, it’s usually a sign that the product’s full of bad stuff—set it down.

5. Compare nutrition facts labels

Always check the serving size first, and don’t assume that what looks like a single serving is just that. You’ll feel like a glutton when you realize you’ve downed 650 calories of juice or 900 calories of chips. If you’re comparing two or more labels, pick the product with larger numbers next to protein, fiber, vitamins, and minerals, and back away from the one that’s higher in sodium, fat, and calories.