It’s easy to think that you’re eating correct portion sizes. You measure a salmon filet by the size of your palm and judge the peanut butter you spread on toast to be no more than a teaspoon.
Yet, studies have found that most people underestimate their portion sizes, especially for high-calorie foods such as peanut butter, nuts, sauces and salad dressings. And if you’re hungry, research suggests that you’ll miscalculate portion sizes to a greater degree than you would after eating a meal.
Studies have also revealed that dieters who measure their food are more successful at losing weight compared to those who don’t.
Enter the food scale, a tool I often recommend to my clients.
If you’re embarking on a meal plan to lose weight, using a digital food scale will ensure you’re not consuming more calories than you think you are. If you’re logging your food intake on an app, weighing food portions will allow you to accurately track your calorie intake.
The food scale advantage
Unless you’re really good at it, the eyeball method of sizing up portions can be off, sometimes by more than 100 calories.
No doubt you’ve heard that three ounces of chicken, fish or meat is the size of your palm. Yet we don’t all have the same hand size.
A palm’s worth of salmon could weigh three ounces, but it could also be six ounces, delivering an extra 155 calories that you don’t account for.
When it comes to whole fruits and vegetables, terms like small, medium and large are subjective. A medium-sized sweet potato weighs 114 grams and has 100 calories while a large sweet potato weighs 180 grams and contains 160 calories.
Measuring cups are quicker and more convenient than a food scale. Keep in mind, though, that the amount of food that fits into one cup can vary, especially for calorie-dense foods like cooked grains, nuts and fruit.
The calories in one cup of quinoa, for instance, will depend on how much of it you pack down in the measuring cup. One cup of diced avocado will likely have more calories than one cup of larger chunks.
These calorie differences may seem small, but they can add up over the course of three meals, day after day, enough to slow down – or stall – weight loss.
A digital food scale isn’t just a weight-loss tool. Weighing protein-rich foods can ensure you’re eating enough of the nutrient to help build muscle in the gym.
Learning portion sizes by weighing foods will also make it easier to recognize right-sized portions when eating in restaurants.
What to weigh, what to measure
If you’re starting a weight-loss plan, weigh calorie-dense foods (e.g., meat, fish, cheese, nuts, pasta, grains) at least initially. Get to know what three ounces of cooked chicken (85 g), one cup of cooked penne (107 g) or spaghetti (124 g, not packed) and one-quarter cup of whole almonds (35 g) looks like.
Keep the food scale on the kitchen counter so you’ll be reminded to weigh your meals.
Use measuring cups and spoons for liquids such as milk and juice, cooking oils, salad dressings and nut butters.
After weighing and measuring foods for a few weeks you’ll be able to eyeball portion sizes more accurately. Pull out the food scale every so often, though, to make sure your portion sizes haven’t crept up, which can happen over time.
Portion control tips
Not everyone wants, or needs, to weigh the foods they eat. And let’s face it, overestimating by half an ounce of chicken or 2 tablespoons of rice isn’t going to prevent you from achieving results.
Another approach: Serve meals on smaller luncheon-sized plates (8 to 9 inches in diameter). The plate will look full and you’ll end up eating less.
Divide your plate into quarters. Fill one-quarter with protein, one-quarter with whole grain or potato and the remaining half with cooked vegetables and salad.
In some cases, weighing foods isn’t recommended. Weighing and measuring foods can become an unhealthy obsession for people with disordered eating.
I also don’t recommend that parents weigh and measure foods in front of their children. Doing so can influence a child’s perceptions about food and healthy eating.
Leslie Beck, a Toronto-based private practice dietitian, is Director of Food and Nutrition at Medcan.
Leslie Beck