Satiety: The Art and Science of Feeling Full

It’s always seemed to me that one of the reasons people shun going on a diet, even when they know weight loss is critical for health reasons, is that they are worried that they’ll feel hungry while on a new diet. Over the two decades I’ve been a vegetarian, I’ve fielded similar questions from people. They ask if I’m always hungry on a vegetarian diet. Sometimes, they believe pop culture myths about vegetarians (and vegans). All we eat is salad. “Rabbit food.” When I’ve felt cheeky about responding to such questions, I’d point to my (overweight) self and say “Does it look like I’ve missed many meals?”


Feeling full is one of the key components to successful weight loss programs and sustainable diets. One reason why many fad diets work initially and then don’t, is because people get tired of the restrictive food choices, and stop eating. They then start getting hungry and they go back to their regular Western diets. You cannot survive for years on just grapefruit.

If you look at the successful weight loss programs, such as Weight Watchers, Mayo Clinic, or the KU Weight Loss Diet, which I am on currently, they have you eating a daily diet that leaves you feeling full, while gradually lowering your calories. Most of the modern obesity and unhealthy diet crisis is caused when people eat too much (and consume too many liquid calories, see upcoming post on this). Any sustainable long term diet, which should be considered a lifestyle, is one where you feel full when you eat healthy foods. One of the objectives of this blog is to discuss the benefits of a Whole Foods, Plant-Based diet (WFPB), which is tasty, nourishing and leaves you feeling full.

Satiety is a core concept of the KU Weight Loss diet that I’m on. It’s built into the food, the program, and the educational program. The idea is that if you are eating healthy foods (and drinking water) which leave you feeling full, your body stops sending you signals that lead to snacking and unhealthy eating. Like most WFPB diets, the emphasis is on avoiding calorie dense foods (like soda, processed foods, burgers, etc.) and eating filling calorie light foods.

satiety ~ the quality or state of being fed or gratified to or beyond capacity. (Merriam-Webster dictionary)

How does this work on my diet? I’ve been on the KU Weight Loss diet for the past five months. I’ve been on the Low Calorie Diet Phase I plan, although I could have left Phase I weeks ago. They also have the Very Low Calorie Diet plan, which is colloquially called the “shake only plan.” It’s designed for people who are extremely overweight, where quick weight loss (over weeks and months), will create immediate health benefits. If you adhere to the guidelines for both diet, you won’t feel hungry very often. I know one person who has been on the shake-only program for five months–they’ve enjoyed a bug weight loss and report having few problems staying on the diet regimen.


The program “does most of the thinking for you.” On the Low Calorie Program, I’m supposed to have three 120 calorie HMR shakes per day, two HMR entrees, and at least 5 servings of fruit or vegetables. Most veggies and fruits are one cup = one serving. Potatoes, beans and legumes are 1/2 cup = one serving. Half an avocado is one serving.

People usually ask me: What about the calories from the fruits and vegetables? I think that one of the chief pitfalls of most diets is being too obsessional about every calorie. While this program does urge us to track most calories, including drinks and the 80 calorie/day max for condiments, fruit and vegetable calories are really not that much. The goal is to get people to shift to a lifestyle where fruits and vegetables are the center of the diet, which will end up being low calorie and filling. The KU program allows you to have more servings each day, but I’ve found that once the weight loss kicks in, I can’t eat more servings. More servings just make me feel stuffed and bloated.

While the caloric restriction built into this program is about weight loss, the serving sizes, especially when it comes to entrees, is about teaching people what normal food portions are on a healthy, long term diet. I will go into this more in a future post.

The core concept underlying the KU Weight Loss program (and similar programs), is calorie density. In other words, most of the processed foods that are the basis of the Western diet are high calories compared to how much they leave you feeling fed (satiety). Think about pizza, meat, pasta, fast food and sodas. How many Americans eat a 1/2 slice of pizza or a small bowl of past, which are normal servings sizes? I think that soda is the best illustration of this concept. Nobody would tell you that drinking a 16oz Coca Cola is a filling meal. It doesn’t even quench your thirst, often making you thirsty for more soda. If you have one 16ox Coke, that’s 140 calories, which is a little but less than half of the calories you should get FROM FOOD during a meal. Most people drink more than one soda a day (or beer), so those calories add up (more on this next week).

Long term sustainable diets, such as the versions of the WFPB diet, are centered around the idea of controlling calorie density and exercise. If you are routinely eating meals and snacks that are centered around fruit, vegetables and whole grains, then you will unconsciously start controlling the calorie density of your diet. Along with exercise, this will keep your weight at stable level for long term health and feeling well!

What about fasting?

The flip side of satiety might be fasting, but is it really? Most weight loss diets counsel against fasting, for good reasons, but more and more research point to occasional fasting as a component of a healthy diet and longevity. I’ll have to read up on this and write up something, but if you are fasting one day every few weeks, it’s not like your body is going to shut down or go haywire. On the other hand, fasting diets do not work, for obvious reasons. Your body requires food. Nutrients. Minerals. After a few days of a fasting diet, your brain has you thinking about food constantly, which just isn’t sustainable. The strength of the KU Diet (and similar) is that it does the thinking for you over the long term. Weight loss happens most effectively over weeks and months, not in the space of one week. But there are health benefits to fasting.

Detox and cleanses?

It’s hard to believe that this nonsense is still around when it was a fad back in the 19th century. Detoxing is an effective process for people with alcohol and drug problems, but for your average person, a detox diet of any kind is nonsense. If you adopt a WFPB or similar lifestyle, you will experience health benefits that are similar to what people think a detox diet does. All of us and the planet, need  to go to a system where ecosystems aren’t poisoned, where people eat healthy diets, and which sustains soils instead of mining the lands. Another problem with detoxes and cleanses is that they are like some kind of short term spa treatment. They may make you feel good for a short time, but why not just switch to a WFPB diet and feel better all the time?

A healthy body is also your best tool if you think you need to cleanse your system. It’s really amazing. Your best ally is your liver, which is your built-in cleanser. So, treat your body well and it will take care of the rest.

Photo: Brooke Lark