Have you ever noticed that sometimes you can feel hungry—really hungry—midway through the morning, even after eating breakfast? Isn’t eating breakfast supposed to get you through the morning without feeling hungry?
First of all, much of the time we want to eat we really aren’t hungry. Hunger is a physiological drive to seek food and is generally experienced as a negative sensation. It is a survival stimulus that got our caveman ancestors out of the cave to seek food, despite the threat of saber-tooth tigers. Hunger is a signal that energy and nutrients are needed and nearly any food will meet this need. In our world now, we rarely need such a powerful stimulus for us to seek food, and most people eat even though they aren’t truly hungry.
What we experience more often is appetite, a psychological sensation that motivates us to eat, usually in response to some sensory input. For example, the smell of fresh-baked cookies makes most people want to eat, even after a meal. In this case, it is the idea of food that triggers the sensation, not a physiological need for nutrients. Additionally, appetite is usually specific to a certain food we crave, like cookies.
One of the problems we face is that we often confuse appetite (wanting something to eat) with hunger (needing something to eat). This can lead to overeating.
It turns out that the foods we eat help determine how much we will eat in a meal and contribute to our feelings of hunger later. A meal that contains a combination of foods providing carbohydrates, protein, fat, and fiber tend to make us feel full sooner, so we may eat less in that meal. By contrast, eating foods that contain primarily carbohydrates, especially refined grains and sugar, don’t have the same effect, and we can take in more calories before our brain gets the signal that we are full. This is called satiation.
That isn’t all. What you eat for one meal can influence how quickly you will feel ready to eat again later. This effect is called satiety. A meal that contains mostly refined carbohydrates can lead to feelings of hunger shortly after a meal. This why you can feel hungry midway through the morning after a breakfast consisting of a donut and juice.
One recommendation to help people eat less to lose weight is to eat foods that are high in fiber such as whole grains, fruits, and vegetables, since these foods tend to make us feel full sooner. Meals that contain a combination of nutrients, especially protein, can also help us go longer between meals.
So instead of a donut and juice for breakfast, try a piece of fruit (fiber!) and something containing protein, like an egg or yogurt.