Tag Archives: appetite

Hunger games

One of the most powerful motivators we have is hunger. Seeking food when we are hungry is what allowed our ancestors to survive. For most of human history, finding the next meal could be arduous or even dangerous, so a strong physiological drive was necessary to make it happen. Now, though, the problem isn’t usually finding food, it’s having access to too much food. Unfortunately, the regulation of hunger in our brains hasn’t changed.

The physiology behind why and when we eat is the topic of my Health & Fitness column in the Aiken Standard this week.

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Hunger is an internal physiological drive to seek and eat food and is usually experienced as a negative sensation. When you are hungry you may be distracted when your stomach growls. Since most of us have a supply of food that is readily accessible, severe hunger is uncommon. But when people diet to lose weight, especially a restrictive diet, hunger can be a powerful signal to eat.

 

Often when we think we are hungry, it isn’t hunger at all—it’s our appetite. Appetite is a psychological, as opposed to physiological, sensation that drives us to eat. Hunger and appetite can work together, but not always. The sight or smell of food can trigger can increase our appetite even if we aren’t hungry. Appetite tends to be more specific, too. While hunger will drive you to eat pretty much any food, appetite usually pushes you to eat a certain food.

 

One of the reasons we overeat is because we confuse appetite with hunger. We may think we need to eat when we see a food advertisement on television or smell someone cooking, but we really don’t have a physiological need for nourishment. Think about eating dessert after dinner. You just ate a full meal, so you can’t possibly be hungry. But when you see the dessert tray you develop an appetite for something sweet, even though you don’t need it.

 

Satiation and satiety are two other factors that influence what you eat. Satiation is the feeling of satisfaction or fullness that signals the end of a meal. Satiety is the effect of one meal, including the amount and type of food you eat, on how much you eat later. You can use these biological factors to your advantage to help you eat less.

 

For example, if you eat quickly you will eat more food (and calories) before satiation occurs. If you eat more slowly, you may actually eat less before that same feeling of fullness occurs. Additionally, what you eat for breakfast will impact when you feel ready for lunch and how much you eat when you do. It turns out that protein has a greater effect on satiety that either carbohydrates or fat. If your breakfast is juice and a donut you are likely to feel hungry sooner compared to having something with protein, like yogurt or eggs.

 

Genetics also play an important role in what we eat. Research suggests that how much we eat and even our food preferences are controlled, at least to some extent, by genes. Of course, some of this has to do with learned behavior, too. Maybe you prefer certain foods because you have a strong positive association with them developed throughout childhood.

 

One important point to remember is that no matter how strong the effect of genetics on food preferences, eating is a behavior that you can control. Your genes give you a predisposition, not a predetermination, meaning that even though you can’t change your genes, you can make an extra effort to not let them define you.


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The mystery of how you can feel hungry shortly after eating breakfast explained.

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?

The answer to these questions gets into why we eat and what regulates feelings of hunger. This is the topic of my Health & Fitness column in the Aiken Standard this week.

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.