Portion Control: How Effective Is It for Weight Loss

by Marixie Ann Obsioma
Published on March 31, 2021 and last updated for accuracy on April 2, 2021

Losing weight is often nonexistent on many people’s to-do lists. While we can all hope to avoid ushering our sedentary lifestyles with yet another weight loss article and tips, significant findings should prompt us to reconsider. 

The newest data released by the Centers for Disease Control and Prevention showed that the weight of adults in the US is continuously rising, with their average BMI now almost at the cutoff for obesity (1) and yet the Food and Drug Administration is implementing changes in the serving sizes of packed foods that could make things even worse, especially for regular consumers of products like ice cream and soda (2). 

Good thing many are now discovering an eminently sensible approach to weight loss, which is portion control. Unlike other fad diets that have yet to stem the increasing girth of American people, this can be adapted to almost any way of life, including most meals that are eaten or taken out. It’s not prescriptive or even intolerant. You will not be asked to cut out any food category, such as fats or carbohydrates, nor deprive you of your favorite foods, including sweets and treats. 

This works! You can keep your weight off without deprivation. You can fill yourself up with delicious, nutritious foods and enjoy a frequent nightcap of your favorite dessert! The main trick here is to put less emphasis on what you eat and focus more on how much you eat! 

Understanding the right portion size for you is important for maintaining a healthy weight and a key ingredient to any successful weight-loss program (3). In this article, we’ll discuss the basics of portion control, how can it help you lose weight and the simple portion-control tricks that you can follow. 

Differentiating Portion Size From Serving Size 

Most problems related to portion size stem from misconceptions about what the term really means. If you use the Nutrition Facts label on food products to direct your portion size, then you are already setting up yourself for a big error! 

What you see on the label is the serving size, the amount of food that is customarily consumed in one sitting as per the US FDA and is not a recommendation of how much you should eat (4). 

Portion size, on the other hand, is the amount of food that you can actually eat. It can be smaller or larger than the serving size printed on the nutrition label. If you confuse these two, your calorie counts will most likely be way off and may destabilize your weight-loss goals. 

Let’s take some good examples. A low-calorie microwaveable popcorn has a serving size of 3 cups according to its Nutrition Facts label. There are 2 servings in each bag. If you take the whole bag, your portion size becomes 6 cups, which is double the serving and double the nutritional values. 

Similarly, the recommended serving size of grapes is 1 cup or roughly 16 pieces. Unless you count them piece by piece, this low-calorie food can increase your carb intake well beyond your intended daily limit. 

This is also true for certain popular diet apps that base their computations on FDA serving sizes. Unless you have the actual reference values and make the necessary adjustments, inputting 8 grapes as a half-portion or 20 grapes as a 1.25 portion, the app will be of less benefit to your weight loss strategy. 

How to Calculate Your Portion Sizes?

There is really no right or wrong amount of specific food to eat if you want to lose weight. The right portion sizes of food are the ones that will fuel your body with energy and nutrients and make you feel satisfied. However, the main goal of any weight loss plan is to consume fewer calories than your body uses to keep your current weight. You have to do this without depriving yourself of important nutrients, including carbs and healthy fats. 

Unlike serving size, your portion size can be calculated based on how many calories you plan to eat daily. You can then plan your menus well by knowing how much of a certain food you can eat to stay within your limit.

Having said that, portion sizes may vary as long as your nutritional needs are being met. To know your correct portion sizes, you will need a weight loss calculator to determine exactly how many calories you need to consume daily to lose weight. The computation will be based on your age, gender, current weight, height, activity level, weight loss goal, and target weight loss date. 

Your goal will help you strategically plan menus around your dietary constraints, selecting not just the foods you should eat but how much you can take. In most cases, it helps to consult a registered dietitian or nutritionist at the beginning to make sure that your diet plan will be safe and effective. 

What Are the Other Health Benefits of Eating Smaller Portions? 

There is a wealth of evidence suggesting that eating smaller portions can offer you several health benefits. While this can be specifically helpful for people who continuously struggle with weight loss, eating smaller meals regularly while still meeting your daily dietary recommendations can also help boost your energy levels and reduce your risk of chronic illnesses. 

1. Increased Energy Levels 

Evidence suggests that eating smaller meals at regular intervals can help boost people’s energy and productivity. This eating pattern can help reduce your perception of fatigue because your brain, which has fewer energy reserves of its own, requires a steady supply of nutrients (5). Eating irregular meals can cause problematic cycles of energy spikes and make you feel less energetic. Having increased energy will likewise help you engage in physical activity, which is good for your health. 

2. Prevents Chronic Illnesses

Smaller meals spread throughout the day can help fight certain diseases. Eating smaller portions more frequently is associated with decreased cholesterol levels and better control of DM (6) as it gives allows better regulation of your blood glucose levels. Be careful if you are taking insulin, though. Consult your doctor first before making reductions in your portion sizes. 

How Does Eating Smaller Portions Help You Lose Weight? 

1. Fewer Calories

Portion control allows you to understand how many calories and nutrients are there in every food and get the correct serving sizes. This helps you consume fewer calories. Of course, you want to control your calorie intake to avoid gaining weight. It has been said that consuming even just less than 100 extra calories daily can cause at least 10 extra pounds in a year. 

2. Healthy Meal Preparations

Controlling your portions and preparing meals often go hand-in-hand. Preparing your own meals makes portion control very easy. You are not just ensuring that you’ll take the correct amount of food; you are also creating an opportunity to fuel your body with healthy, weight-loss-friendly foods! 

3. More Energy 

As mentioned earlier, one great benefit of controlling your portion sizes is that it gives you more energy. Instead of feeling sluggish after meals because of food coma and getting cramps, you will feel more energized to get into training for body strengthening, toning, and slimming. 

4. Better Digestion and Metabolism

Controlling the amount of food you eat will also help improve your digestion. Sometimes, overeating causes constipation. By eating smaller portions of nutrient-packed foods, you will rarely feel that discomfort and be able to digest your food more efficiently. 

Spreading your calories out throughout the day by nibbling more often than scarfing huge amounts of food all at once will also boost your metabolism (7). 

5. Good Mindset

With regular practice of portion control, you’ll get a better understanding of how much food your body needs and how you should be feeding it. This will change your mindset, and it will follow you wherever you go, whenever you are eating. Even if you go to restaurants, you know exactly that the food on your plate is not necessarily one serving and that you are not obliged to eat it all. You should be able to stop yourself from eating as soon as you feel satisfied. This will certainly help you drop more pounds and keep them off! 

6. More Nutrients 

Portion control, as we have mentioned earlier, will allow you to choose and prepare your own meals. This means feeding yourself with the essential amount of nutrients in a limited amount of calories. You can get the right amounts of fruits, veggies, carbs, protein, and healthy fats. You’d be amazed just how much veggies can fill you up and keep you satisfied! 

7. Less Restricting 

Restrictions appear to be one of the major causes of binge-eating and, therefore, a major factor in why many people fail in losing weight. On top of that, restriction makes people unhappy, sometimes causing depression. By allowing yourself to eat smaller portions of the food that you like, you will not feel disheartened and makes it easier for you to stick to your weight loss regimen. 

Tips to Effectively Reduce Your Portion Sizes 

When you are trying to lose weight, you are asked to eat less. But how do you scale back your portions without feeling hungry? Thankfully, there are now easy strategies you can follow to reduce the amount of food you eat while keeping hunger at bay. 

1. Switch to Smaller Dinnerware 

Evidence shows that the sizes of your plates, spoons, and glasses can intuitively influence the amount of food you eat (8, 9, 10). If you use larger plates, your food may appear smaller, hence causing you to overeat. Interestingly, most of us were completely unaware of this effect and change in portion size, including nutritional experts (11)! They served themselves 31% more ice cream when given big bowls and 14.5% more when provided with bigger serving spoons (12). 

Therefore, changing your usual plates, bowls, and serving spoons for smaller sizes can help reduce your food intake. Many would feel just as full having consumed smaller dishes as from a large one. 

2. Follow the Half-Plate Rule 

Fruits and vegetables contain high amounts of filling fiber and water with fewer calories (13). By replacing half the protein or starch of your meal with fruits and non-starchy veggies, you can eat the same amount of food and still slash total calories. 

Evidence has shown that the amount of food you eat is a great factor in feeling full and satisfied (14). One study gave participants the same amount of pasta, but with varying amounts of veggies, results showed that those who had the highest proportion of veggies ate the least amount of calories without them knowing (15). 

Filling half of your plate with colorful fruits and veggies will still make your meals look appetizing. You can also try this when making mixed dishes. Add more vegetables to your favorite recipes to lower their calorie content. 

3. Use Your Plate As A Portion Guide

While measuring and weighing food is not appealing, you can still do portion control with the help of your plate or bowl as guides. This can help you create a well-balanced meal, following the optimal macronutrient ratios. A rough guide for every meal is: 

  • Half a plate for vegetables or salad
  • A quarter of a plate for high-quality protein such as meat, fish, poultry, eggs, dairy, beans, and tofu 
  • A quarter of a plate for whole grains and starchy veggies
  • Half a tablespoon for high-fat foods like oils, butter, and cheese

Keep in mind that this is just a rough estimate, as we all have different dietary needs. Those who are physically active may need more. Vegetables and salad contain less amount of calories but are rich in fiber and other nutrients. Filling up on these will help prevent overeating of calorie-dense foods. For more guidance, you can look for portion-control plates. 

4. Your Hands May Work As A Serving Guide

Another good way to check an appropriate portion size without the aid of any measuring tools is by simply using your hands. Your hands correspond well to your body size. Bigger people who need more food generally have bigger hands (16). An estimate for every woman’s meal includes: 

  • A palm-sized serving of high-protein foods like meat, poultry, fish, and beans 
  • A fist-sized portion of vegetables and salads 
  • A cupped-hand portion if high-carb foods like whole grains and starchy veggies
  • A thumb-sized serving of high-fat foods like oils, nuts, and butter

For men, double the measurements! 

5. Ask for Half A Portion When Dining Out 

Restaurants attract customers by serving large portions (17). On average, their serving sizes are about 2.5 times bigger than the standard. Sometimes, it can go as high as 8 times bigger! (9, 17, 18). 

While you may think that this is good to get the most out of your money, you are wrong! To save you from calories and overeating, just ask for a half portion. Alternatively, you can share a meal with someone or order a starter instead of the main dish. Another tip is to avoid buffet-style, eat-all-you-can restaurants where it is easy to overindulge. 

6. Eat Protein With Every Snack or Meal 

Scientific studies have repeatedly shown that protein can increase feelings of fullness more than fat and carbs (19, 20). Take good advantage of protein’s filling properties by including it in your snacks and meals. 

Focus on getting it from lean sources like eggs, skinless poultry, fish, seafood, and dairy. Plant-based proteins are also excellent choices! Take beans, tofu, and nut butter! You may also do the following tips to get a good protein boost: 

  • Add plain Greek yogurt to your breakfast smoothie
  • Add string cheese or hummus to your whole-grain crackers
  • Poach an egg in your vegetable soup
  • Add hard-boiled egg or beans to your salad

7. Start Your Meals with A Glass of Water

Drinking water for at least half an hour before a meal can naturally help in portion control. It will make you feel less hungry and get a better distinction between hunger and thirst. 

Evidence showed that drinking approximately 500 ml of water before every meal can result in a 44% greater decline in weight over 3 months, most likely because of less food intake (21). It may also help you consume 13% fewer calories without trying to make any changes (22). 

8. Get A Salad or Vegetable Soup For Appetizer

It may seem counterintuitive to add more courses in order to eat less food, but starting your meal with a salad or soup can help you do just that! 

Evidence showed that taking soup before an entrée can help you eat 20% fewer calories for your entire meal (23). You’ll most likely get the same results if you take salad before your favorite pasta (24). Salads and light vegetable soups both have high water and high fiber content. This combo appears to be an effective way of curbing appetite and subsequent calorie intake (25). But check your salad dressing as it can easily rack up your calories! 

9. Eat Slowly and Mindfully 

Eating too quickly makes you less aware of getting full. Your brain needs approximately 20 minutes to register feelings of fullness after eating a meal; therefore, eating slowly can greatly help reduce your total intake and make you enjoy your food more (26)! 

Also, eating on the go or with distractions such as TV and other gadgets increases your likelihood of overeating (27). Mindful eating, the practice of paying attention to what you eat without any distraction, will help your notice hunger and fullness cues better, so you will know exactly when you already had enough (28). It will help you differentiate physical hunger from emotional hunger. 

Focusing on your meal and refusing to rush will help you control your portion sizes better. Experts recommend taking smaller bites and chewing them thoroughly, at least 5-6 times before swallowing (29). If you are always eating out of emotions, try doing other activities before eating a meal. You can go for a short walk, exercise, drink tea, or write a journal. 

The Bottomline

Unwanted weight gain often starts with large portion sizes. Good thing, there are several practical steps you can follow to control your food intake. 

Eating several small meals is believed to be more effective for weight loss. This is one way of ensuring you consume fewer calories, sugar, and fat per sitting. Bulking up your portions with lean protein and veggies can help too! The use of smaller plates, drinking water before meals, and eating slowly will likewise reduce your risk of overeating and encourage you to do mindful eating. 


  1. https://www.cdc.gov/nchs/data/nhsr/nhsr122-508.pdf
  2. https://www.fda.gov/media/99331/download
  3. https://www.nature.com/articles/ijo201482
  4. https://www.fda.gov/food/nutrition-education-resources-materials/new-and-improved-nutrition-facts-label
  5. https://www.health.harvard.edu/healthbeat/eating-to-boost-energy
  6. https://www.diabetes.co.uk/portion-control.html
  7. https://www.ncbi.nlm.nih.gov/pubmed/2674713
  8. https://www.ncbi.nlm.nih.gov/pubmed/15761167
  9. https://www.ncbi.nlm.nih.gov/pubmed/20470810
  10. https://www.bmj.com/content/331/7531/1512
  11. https://www.ncbi.nlm.nih.gov/pubmed/18823179
  12. https://www.ncbi.nlm.nih.gov/pubmed/16905035
  13. https://www.ncbi.nlm.nih.gov/pubmed/14995052/
  14. https://www.ncbi.nlm.nih.gov/pubmed/16002828
  15. https://www.ncbi.nlm.nih.gov/pubmed/9497184
  16. https://www.ncbi.nlm.nih.gov/pubmed/16187319
  17. https://www.ncbi.nlm.nih.gov/pubmed/12589331
  18. https://www.ncbi.nlm.nih.gov/pubmed/16963346
  19. https://www.ncbi.nlm.nih.gov/pubmed/18469287
  20. https://www.ncbi.nlm.nih.gov/pubmed/23107521
  21. https://www.ncbi.nlm.nih.gov/pubmed/19661958
  22. https://www.ncbi.nlm.nih.gov/pubmed/18589036
  23. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2128765/
  24. https://www.ncbi.nlm.nih.gov/pubmed/15389416
  25. https://www.ncbi.nlm.nih.gov/pubmed/28131006
  26. https://www.ncbi.nlm.nih.gov/pubmed/18589027
  27. https://www.ncbi.nlm.nih.gov/pubmed/24462489
  28. https://www.ncbi.nlm.nih.gov/pubmed/24636206
  29. https://www.ncbi.nlm.nih.gov/pubmed/24215801
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