By Jennifer Michaelchuk, RD
Have you noticed? There seems to be a lot of love for protein lately. Protein is popular because it helps with satiety and feeling full. This is great news when you are trying to eat less and manage weight. But, before you stock up on protein bars, there are a couple of things to know about “filling up” with protein.
Appetite and satiety are complex.
I don’t often think about what is happening in my body when I sit down to eat a meal, but what is going on is amazing. When you eat, there is a “conversation” between your gut (gastrointestinal system) and your brain (neurological system) to make sure you stop eating when you are full. Hormones and other signals, like the stretching of the stomach, tell our brains
- we have eaten enough (satiation); this can take up to 20 minutes
- how long we stay full and satiated
- when we need to eat again
Many things can influence satiety, including the
- mix of macronutrients in the meal (protein, carbohydrate, fat)
- amount and type of fibre in the meal
- form of the food eaten (solid versus liquid)
- energy density or the amount of energy (calories) per gram of food
Even though we have this internal feedback system, we often override it – continuing to eat even when we are stuffed, and ignoring it when we are hungry. Our appetite can be influenced by many elements:
- portion size
- variety of food available
- sensory quality of food (how delicious we perceive it to be)
- distractions such as phones or television
- the amount of sleep we get
Protein increases satiety, but we do not have all the information.
Protein influences the hormones that signal our brain that we have eaten enough. A 2016 scientific review published in the Journal of the Academy of Nutrition and Dietetics reinforced evidence that protein is more filling compared with carbohydrate and fat. This meta-analysis combined data from five studies. When overall eating was controlled, the study concluded that higher protein intakes increase fullness ratings more than lower protein intakes.
Not only does protein fill us up right after a meal, it also may increase satiety over a 24-hour period. That is why eating protein at breakfast may help with controlling appetite and cravings later in the day.
Scientific research has revealed a lot about protein and satiety but much remains to be learned. For example, the specific amount and timing of protein intake for optimal satiety is not known, and different types of proteins may have different effects. For example, casein, a protein found in milk, is digested slowly, and therefore may increase satiety. However, more research is needed.
What to do
Here is my advice based on what we know about protein and satiety:
- Spread your protein intake over the day, and aim to get 20-30 g at each meal, the amount the body can use at one time to maintain muscle and other tissues. This is as important as getting enough total protein.
- Focus on breakfast, as this tends to be a more challenging meal to get enough protein. It also may help to control intake later in the day.
- Combine your protein with vegetables, fruit and whole grains to ensure you are also eating enough fibre.
- Eat slowly, so your stomach has time to tell your brain it is full.
- Listen to your body, and eat mindfully.
- Don’t rely solely on protein foods to keep your appetite in check. Make sure to eat regularly throughout the day and get enough sleep.
When it comes to healthy eating, I like to keep the big picture in mind. While protein plays a part in satiety, the process is complex.
This article was originally posted on Nourish Move Thrive Filling Up with Protein? What you need to know about protein and satiety.