We’ve all been there: after enjoying a quick snack, we check the nutrition label only to learn we’ve just eaten two, three or even four servings when we thought we were having one.

Our food industry tends to double, triple or even supersize servings and restaurants are notorious for putting way more food on a plate than anyone other that an intense athlete should eat, leaving us perpetually over-served. Unfortunately, many of us have visually adjusted to these big serving sizes and are unaware of what an accurate portion looks like.

If we can reprogram our brains to see healthy servings sizes, then maybe we won’t be fooled when it comes to being over-served. This guide — using a medium adult hand as the visual clue — should help.

SERVING SIZE VS. PORTION SIZE

A serving size is a measured amount of food — 1 cup, 1 slice, 1 bag, etc. — intended to be eaten at one time. It’s the amount you’ll see on a food label, and it’s what the USDA uses in the Dietary Guidelines for Americans.

A portion size, by contrast, is the amount of food or drink you actually consume in one sitting, whether an entire rack of ribs with all the fixings or a single apple. The goal of this guide is to help you match your portions to recommended serving sizes.

1 cup is the amount that fits in a mounded pile in the palm of a medium adult hand or about the size of a tennis ball. It provides approximately 200 calories and 50 grams of carbohydrates.

Granola is best used as a topping or mixed in with cereal, instead of eaten by the  bowl-full. A little goes a long way. Be careful with the serving sizes on the granola box. It could say 2/3 cup, which is more than twice the recommended amount. See above for what 1/4 cup looks in a medium adult hand: it should just cover the center portion of your palm.

1 serving of dried fruit or nuts is 1/4 cup (40 grams), which fills the center of the palm of a medium adult hand. Similar to granola, it’s best to spread this throughout the day or add it to a flaky cereal or a healthy trail mix. Also, avoid dried fruit that contains added sugar –– it’s best to save those calories.

One medium piece of fresh fruit is about the size of a small fist or 3–4 inches in diameter. Aim for 3–5 servings of fruit per day — and since dried fruit is so calorie-dense, opt for fresh first.

A serving of leafy greens is technically 1 cup, but this is one time where we recommend doubling or tripling the portion — 2 cups is about what two medium adult hands can pick up in a single go.

Non-starchy vegetables include broccoli, cauliflower, cucumbers, asparagus, peppers, mushrooms, tomatoes and onions. 1 cup of chopped, non-starchy vegetables creates a mounded handful in a medium adult hand.

Starchy vegetables like corn, peas, parsnips, potatoes, pumpkin, squash, zucchini and yams are higher in carbohydrates and therefore more calorie-dense –– all the more reason why knowing the portion size is important. As with non-starchy vegetables, a serving of starchy vegetables fits in an average adult hand.

A 3-ounce piece of fish, poultry or meat is about the size of a deck of cards or the whole palm of your hand. Focus on lean proteins such as chicken, turkey, fish, seafood or lean cuts of beef and pork.

A serving of cheese is about the size of your index finger or 4 dice. Most 1 1/2-ounce servings are around 150–165 calories, so a little goes a long way. Adding just a slice or nibble of real cheese to your diet can be a great source of calcium. Cut into slices or shred and add to a salad.

Depending on what variety you buy — skim, reduced-fat or whole — 1 cup of milk provides anywhere from 90–145 calories. In an average-size glass (not a tall and skinny one), 1 cup measures about the size of a small fist.

Use these guides to determine how much to eat, not how much you’re served. Being able to assess servings and the portion sizes you want visually is a big help when you’re trying to lose weight, especially when it’s time to eat out.