Understanding Portion Sizes: How Much Are You Really Eating?

You only meant to eat a couple of crackers. But once you reached into the bag, you just kept going … and going … and going…

When you’re trying to get or stay healthy, choosing nutritious foods is important. But there’s more to it. You also need to pay attention to how much food you’re eating, which is where portions come into play.

Registered dietitian Julia Zumpano, RD, LD, explains what portion sizes are, why it’s so important to pay attention to them and how to practice portion control in your everyday life.

What is a portion size?

It can be easy to confuse serving sizes and portion sizes, especially because there’s lots of overlap in the ways we discuss them. Zumpano breaks them down:

1. A serving size is a specific amount of food, like what’s noted on a nutrition label. Serving sizes tell you the amount of calories, fat, sugar and various nutrients in that indicated amount of food — but that doesn’t necessarily mean that a serving size is how much you do eat or even how much you should eat.
2. A portion size is what fills your plate. It’s how much of a food you eat, whether that’s more or less than a serving size of that food.

Let’s use almonds as an example. A serving size of almonds is 1 ounce, or about 23 almonds, which amounts to around 160 calories. But if you eat 46 almonds, your portion size is double the serving size, which means you’re getting twice the amount of calories and nutrients.

“Nuts are a great example of a healthy, nutrient-rich food that should be consumed in small portions,” Zumpano says. “It’s easy to eat a lot of them at a time without realizing how high in calories they are.”

Why portions matter

Practicing portion control is one of the best ways to adjust your diet to achieve and maintain a healthy weight. Even if you’re not trying to lose or gain weight, being aware of recommended portion sizes helps you take in the right amount of nutrition.

“Paying attention to portion sizes can help you manage your weight and limit the amount of sodium, sugar and fat you consume,” Zumpano says.

Knowing how to manage your portions is especially helpful during social events and the holiday season, when festive parties and rich meals abound. (Hello, homemade cookies in the break room!)

“Meals and snacks around the holidays tend to be higher in fat and sugar,” Zumpano notes, “but choosing smaller portions of these foods can prevent you from overindulging.”

How to learn portion control

So how can you start to get a handle on portion sizes? Learn how to read nutrition labels on food packaging and check them for everything you buy. Look for the number of servings in each container and the nutrients per serving.

The best way to determine the amount of food in a given serving is to look at the nutrition label and measure it out, Zumpano advises. Get in the habit of whipping out a measuring cup and filling it with the proper-sized portion of foods, like vegetables and rice, then emptying it onto a plate. This will help you learn what these serving sizes look like.

“When you do this, take note of how much of the plate is covered,” she says. “It takes extra work, but eventually you’ll become much better at learning to ‘eyeball’ amounts of food to know whether it’s too much or too little.”

Examples of portion sizes

“What we consider a heart-healthy plate starts with a standard nine-inch plate,” Zumpano explains. “Then, you want to think about dividing that plate in half visually.” Here’s how much space each type of food should take up.

• Half a plate of vegetables: Vegetables should take up the largest portion of your plate.
• A quarter-plate of lean protein: Imagine that the other half of your plate is divided into two quarters. “Fill up one of those quarters with some type of lean protein like chicken, turkey breast or fish,” Zumpano says. “That amount should be about the size of the palm of your hand.”
• A quarter-plate of complex carbs: For the final portion of your plate, choose a complex carbohydrate like whole wheat pasta, brown or wild rice or sweet potatoes. “Whatever starch you choose, you want to keep it to about a cup, or the size of your fist,” Zumpano says.

Of course, portion sizes aren’t the only factor in a healthy meal. It’s also important to limit condiments and toppings that add unwanted fat and sodium to your meal — think gravies, butter, cream sauces and cheese.

“That’s where we add a lot of extra fat, salt and calories to a meal,” Zumpano warns, “so try to keep it as simple as possible. For extra flavor, you can add herbs, a drizzle of extra virgin olive oil or even a little bit of mustard, which is low in sodium and fat.”

This quick portion size guide, which compares suggested serving sizes of foods with familiar objects, can help you better understand how much to put on your plate.

Tips for watching your portion sizes

Scaling back on your portions can take practice, patience and a little bit of time. Zumpano shares some tips to help you hack the process of teaching yourself this healthy habit.

• Use smaller dishes. Less space on your plate means an easier time managing portions, so reach for a nine-inch lunch plate rather than an 11-inch dinner plate.
• Portion out food ahead of time. When you meal prep or store leftovers, put them away in separate, portion-controlled amounts for easy retrieval. When the time comes to eat, you can dig right in without on-the-spot math and portion prep.
• Snack smart. Steer clear of miniature snacks, like tiny crackers, cookies or pretzels. “Most people end up eating more of these than they realize, and the calories add up,” Zumpano says. The same is true when you eat right out of the bag or carton, or when you “pick” at a platter of food left sitting out — like charcuterie boards and holiday spreads. Instead, measure them out and put them into a small bowl to keep your portions in check.
• Be wary of restaurant sizing. Portions are usually very big at restaurants, so share a dinner entree or ask for a lunch-sized portion instead. You can also ask for a box at the start of your meal, then box up half of your portion before you even begin to eat.