Serving Size vs Portion Size

This blog looks at the difference between serving size and portion size and its impact on nutrition. The difference between serving size and portion size can be crucial for maintaining a healthy lifestyle.

Both sound like one and the same thing, however they represent different concepts that can have a significant impact on eating habits, weight management an overall health. Misunderstanding the difference between serving sizes and portion sizes can lead to overeating or undereating, impacting your nutritional intake and well-being.

Let’s look at the difference between the two and then try our top 5 tips at the end.

What is a serving size?

A serving size is a standardised, measured amount of food or drink. It is often found on a food label and serves as a guideline for what is considered a typical or recommended amount for eating or drinking. Serving sizes are determined by government regulatory bodies like the Food and Drug Administration (FDA) in the U.S., or are based on the amounts that people typically eat in a single sitting according to national dietary surveys.

Serving sizes are used for many purposes such as:

Nutrition Labels. Food manufacturers use serving sizes to inform you of the nutritional content of their product including calories, fat protein, carbohydrates and other nutrients – these are all given ‘per serving size’. If a packet of crisps has a serving size of 40g but the amount in the bag is 120g and you eat the whole packet, then you are eating three times the number of calories and nutrients listed on the label.
Dietary guidelines. Serving sizes also help set dietary guidelines, which provide recommendations for how much of each food group an individual should eat daily. For example, UK dietary guidelines might recommend that adults consume 5 portions of fruit daily. This recommendation is based on standardized serving sizes that ensure consistency in dietary tracking and nutritional planning.

Serving sizes help create a baseline understanding of food intake, but they don’t necessarily reflect how much people will eat in one sitting, which leads to the concept of ‘portion size’.

What is a portion size?

A portion size refers to the amount of food someone chooses to eat in one sitting, which can be larger, smaller, or the same as the serving size. Portion sizes are very personal and can differ significantly based on a number of variables, including hunger, the kind of food being eaten, cultural norms, and even the size of the plate or bowl being used. Unlike serving sizes, which are determined by regulatory authorities, portion sizes are controlled by individuals. For example, if the serving size for pasta is 70g but someone chooses to eat double that amount in one meal, their portion size is double the recommended serving size. While there’s nothing fundamentally incorrect with eating more or less than a serving size, consistent over-eating or under-eating can lead to nutritional imbalances and other health issues.

Portion sizes can be influenced by a variety of factors:

Cultural norms. In some cultures, larger portion sizes are the norm, especially in social settings like parties or family dinners. Over time, repeatedly eating large portions can contribute to weight gain, as people often eat more than they need to feel full.
Environmental prompts. The size of packaging, plates or bowls can affect how much a person eats. Research has shown that larger plates or packaging can trick the brain into thinking more food is needed, leading people to eat more than necessary.
Emotional and psychological factors. Stress, boredom, or habit can cause individuals to serve themselves larger portions without realising it, which can lead to overeating and weight gain.

It’s important to understand the difference between serving size and portion size in order to have a balanced diet. Many people mistakenly assume that the amount of food they serve themselves is equivalent to the serving size recommended on a package or by dietary guidelines. However, portion sizes can easily exceed serving sizes, especially when eating out at restaurants or during holidays, where ‘portion distortion’ is common.

For example, a restaurant meal can be several times the recommended serving size. If a standard serving of steak is 3 ounces, but a restaurant serves a 12-ounce steak, the portion size is four times that of the serving size! Eating the whole steak in one sitting means eating four times the calories, fat, and other nutrients, which can contribute to overconsumption and long-term health issues like obesity, diabetes, and heart disease.

How to manage portion sizes

While it’s important to pay attention to serving sizes, managing portion sizes is a more practical step for maintaining a healthy diet. A great way to do this is to prepare your meals in advance by meal prepping and preparing. Have a read of our blog on meal prepping: Meal Prep like a pro! – W Fitness

As promised, here are our top 5 tips on how to manage your portion sizes whilst still ensuring that your meals remain balanced:

Use smaller plates and bowls. Research shows that people eat less when using smaller plates. Smaller plates make portions appear larger, which can trick the brain into feeling satisfied with less food.
Pre-portion snacks and meals. Instead of eating straight from large packets or containers, divide food into smaller, individual servings. Pre-portioned snacks or meals can help prevent mindless overeating and make it easier to stick to appropriate portion sizes.
Pay attention to hunger cues. Listen to your body’s hunger signals and avoid eating out of boredom or stress. Eating slowly and being mindful of how full you feel can help you avoid overeating.
Check food labels. Understanding the serving size on a nutrition label can help you gauge how much food you are actually eating. If a package contains multiple servings, be mindful of how much you eat and adjust the amount accordingly.
Share restaurant meals or save leftovers. Since restaurant portions tend to be larger than one would normally eat, consider splitting a meal with a friend or taking the leftovers home for later. This helps avoid overeating while still enjoying the experience of dining out, and, as a bonus, you get lunch for the following day too :)

Conclusion

The difference between serving size and portion size is more than just a matter of semantics; it plays a crucial role in how we understand and manage our food intake. While serving sizes provide a standardised reference point for nutritional content, portion sizes are flexible and can easily exceed these recommendations without careful attention. By being mindful of portion sizes, you can adjust your eating habits according to nutritional guidelines, leading to a healthier, more balanced diet. Understanding this distinction is key to improving personal health, combating overeating, and preventing chronic diseases linked to poor dietary habits. Visit us at W Fitness to see how we can help with your health and fitness journey :)

Much Love

Caroline & Hannah xx