The Lifesum Guide to Portion Size

Let’s start with calories. You don’t need to worry too much about these when it comes to portion size, but I like to use them to think about how …

While I’ve never necessarily been extremely overweight, or had any kind of eating disorder, I’ve definitely always had a somewhat complicated relationship with food when it comes to knowing how much to eat.

I grew up with fairly large portion sizes at home, and we always had to finish whatever was on our plate. My parents meant well, obviously, but it meant that I grew up eating a lot. When I was younger, this was fine because I had teenage metabolism, but as I’ve grown older and I inch closer and closer to my thirties, my metabolism has slowed, and I’ve actually noticed that I don’t feel all that great after meals where I’ve eaten too much (what a shocker!).

With all that said, I thought it might be helpful to put together a guide that shows you roughly how much you should be eating in your meals, along with practical ways to eyeball it (because none of us want to carry around measuring cups, although you know, why not? You do you!).


Let’s start with calories. You don’t need to worry too much about these when it comes to portion size, but I like to use them to think about how I distribute my calories in my portions and across meals throughout my day. In Lifesum’s app, you simply enter all your information; height, current weight, age, goal weight; and it calculates what you should be aiming for calorie-wise each day. To maintain my weight, I need around 2,290 calories a day, but for moderately paced weight loss, I’d be looking at 250 fewer calories each day. Split that across 5 meals (Breakfast, mid-morning snack, lunch, mid-afternoon snack, dinner), and that works out as 408 calories in each meal (5 small meals), or three larger meals at around 580 calories each, and two small snacks at 150 calories each.

Here’s the tricky thing about portion size: it’s harder than simply eyeballing your portion. You’ll know this if you’ve read some of our blog posts about calories and how they are made up; all calories are not equal. For example, there are fewer calories in a large bowl of broccoli than there are in a large bowl of pasta and meatballs. Because of this, portion size has a lot to do with food group or food type.

If you’re thinking about how to distribute the different food groups across your plate, the recommendation is typically vegetables 50%, 25% starch (potatoes, pasta, rice), 25% protein. This is a pretty good guide, but depending on the size of your plate, you could end up drastically over- or undereating. I think it’s better to take yourself into account, and use yourself to gauge how much you need to eat. You can actually use your hand to measure how much food you need, which I think is smart. A serving of protein in a meal is about the size of the palm of your hand, a serving of vegetables is about the size of your closed fist, a serving of fats is the size of your thumb, and a serving of carbs is about the size of one cupped hand. Experts recommend upwards of five servings of vegetables in a single meal, and around three servings of fats, proteins, and starches.

If this seems like very little food, it might be because you, like me, are used to eating way more than you need to, or it could be because as a very active person, you need a little more to sustain you each day. If it’s the former, I’d say, start listening to your body after you eat as you usually do; how do you feel? Lethargic, heavy, like you can’t breathe because you have food up to here, or like you desperately need to get to the bathroom? These are the cues your body is giving you that you need to eat less, and you should lean into them, but slowly. Plate your food on a smaller plate, and have healthy snacks on hand if hunger does kick in. If you’re actually someone that needs more calories than the average joe, then I’d recommend not adding more to your plate, but going for more nutrient-dense foods, rather than upping your portion. Skip low fat options and opt for full fat, eat foods with more fiber, and make sure to avoid empty calories (like those in candy or a bag of chips); that’s the key to making sure you have the nutrients you need, the calories you need, and the energy you need to get through each day.

Happy eating!

All of the content and media on Lifesum is created and published for information purposes only. It is not intended to be used as a substitute for medical advice or treatment. Users should always consult with a doctor or other health care professional for medical advice. If you have or think you are at risk of developing an eating disorder, do not use the Lifesum app and seek immediate medical help.