At first glance it may seem that there are many similarities between the two, but in truth they are very different, in both motivation and in practice.

Calorie Restriction practitioners acknowledge that there is a danger that this style of eating might attract or lend legitimacy to anorexics, and questions sometimes arise about the differences between the two.

Anorexia: It's All About Appearance

The motivation for anorexia is the mirror: "How do I look? Am I thin enough?" The answer is always "No." If you are anorexic, no matter how skinny you get you always look fat to yourself.

Calorie Restriction: It's All About Health

For calorie restriction the motivation is longevity and health: forestalling aging and the onset of disease. Some CR practitioners aren't any thinner than people eating an ordinary diet. Calorie Restriction is not about appearance. CR is about cutting calories while maintaining excellent health.

Calorie Restriction practitioners try to find physicians who are informed about the research in the field; and who can support and supervise the maintenance of healthy blood parameters, musculoskeletal condition, and other markers of physiological and psychological health.

Anorexia: I Am Bad

The inner monologue of anorexics is one of judgment. Absolute perfection -- which means total abstinence from food -- is the only acceptable criteria for the anorexic, so he or she is doomed to failure for being imperfect, for having to eat at all.

An anorexic feels deserving of punishment and deprivation.

An engine of self-hate drives anorexia: "I am bad when I am fat. And I am always fat."

Anorexics report superficial feelings of "self-righteousness" for abstaining from food, but these are ephemeral, and only skin-deep. Inside the anorexic brews a cauldron of relentless self-criticism and despair.

Calorie Restriction: I Am Good

The inner monologue of a CR practitioner is "Calorie Restriction is worth the effort because it may prolong my life and health."

A CR practitioner feels deserving of good treatment. An engine of self-love drives the practice of CR.

Anorexia: No Cheating Allowed

The rules of Anorexia say: Eating is Cheating. The rules of anorexia forbid cheating.

So an anorexic is faced with a terrible no-win dilemma: Should I break the rules, eat, and hate myself for my weakness, my failure, and my fat?

Or should I do what I "should" and face death by starvation?

Either way, an anorexic is doomed to failure.

Calorie Restriction: Cheating Allowed

Calorie Restriction is not a "dogma" nor is it rigidly defined. There are many different ways to achieve CR, and every CR practitioner finds his or her own method.

Practicing Calorie Restriction is like getting exercise: You do whatever works for you.

Some CR practitioners eat like they've always eaten but omit a meal here or there. Some take periodic fasts. Some eat many small meals throughout the day, limiting the calories of each. Some limit the amounts of some foods while allowing themselves to have as much as they want of others.

There are almost as many paths to Calorie Restriction as there are people practicing it. But whatever the path, all strive to obtain optimum nutrition from the fewest number of calories. CR does not have rules and does not impute judgment to any particular diet or way of eating.

Anorexia: Hidden and Secret

Anorexics try to hide their passionate pursuit of thinness by pretending to be eating when they're not, by sneaking diet pills and other substances to kill their appetite, and by lying to friends and family.

The life of an anorexic is a lonely one.

Anorexia is an addiction, and, though a "friend in the night," an addiction is a non-human, tyrannical friend. The anorexic is married -- secretly -- to a cruel and abusive spouse; with nowhere to go for real human contact, comfort, or acceptance.

Calorie Restriction: Open and Public

Calorie Restriction practitioners are a proud bunch, and happy to talk about their determination to try to beat back aging and disease.

Practicing CR means that you like yourself and you like living. Who wouldn't want to share that lust for life with others?

If anything Calorie Restriction practitioners tend to err on the side of too much "missionary zeal," wanting to spread the word of the astonishing research pouring in, in the field of caloric restriction and longevity, in recent years; and the even more astonishing implications this research might have for human life.

Anorexia: Black-and-White Thinking

Anorexia is about extremes. Anorexics inhabit a world of good and evil, perfect or flawed -- there is no middle.

For an anorexic eating is an "on/off switch." You're good when you don't eat, and bad when you do. It is the simplistic, black-and-white thinking of a child who wishes to transcend the subtleties and complexities of what it is to be human.

Calorie Restriction: The Gray Area

Calorie Restriction is about moderation. To practice CR one cannot just stop eating, but instead must do the harder thing of continually figuring out how much food, how much caloric restriction, how to get a full supply of nutrients, and how to balance exercise, stressors, and lifestyle issues.

Calorie Restriction is not "either/or". CR can range from "very mild" to "moderate" to "extreme;" and can change with circumstances and over time. Every CR practitioner decides what works best.

Calorie Restriction demands more thinking than anorexia because eating, like the rest of life, is imprecise. Where anorexic thinking is child-like, CR requires the "grown-up" understanding that life is lived not in the simpler "black and white" but in the ill-defined, messy complexities of the "gray area."

CR requires the acceptance of oneself - and the act of eating -- as imperfect.

Anorexia: Obsessed With The Scale On Your Bathroom Floor

… and the full-length mirror on your wall … and the scale at your gym … and your pants' size … and that fat globule on your left earlobe …

Calorie Restriction: Obsessed With The Scale On Your Kitchen Counter

While "obsessed" might not be the word you want to aim for, if you are going to obsess the kitchen scale is probably better than the bathroom scale. At least you're in the right room!

But weighing every morsel of food isn't the preference of most Calorie Restriction practitioners.

Successful, long-term practitioners of CR, healthy in mind as well as body, try to unleash themselves from the kitchen scale once the initial logistics of practicing CR are worked out and the number of calories in different portions becomes second nature.

The majority of CR practitioners never use a scale at all.

Anorexia: Eating is Bad, and Food is a Bad Thing.

For anorexics every aspect of food and eating is negative. Dread is the constant companion of the anorexic.

Calorie Restriction: Eating is Good, and Food is a Good Thing

A CR practitioner loves to eat. CR practitioners view food as welcome nourishment for body, mind, and spirit.

Nutritious foods are, indeed, delicious: fresh salads, clean vegetables and meats, healthy combinations of fresh ingredients. Farm families will attest that good food doesn't need to be dressed up and disguised to taste great. Good quality ingredients do indeed taste good.

Eating can be one of life's great joys, and the enjoyment of food can be part of a successful calorie restriction program.

Some CR practitioners find that they struggle initially to "wean" themselves from diets of junk foods, empty calories, and addictive substances. There is a learning curve for those who have eaten poorly for many years. But most find that once the new ways of eating become habit food simply tastes better and meals are more satisfying than ever before.

Many CR practitioners learn for the first time what it feels like to actually experience being hungry. Hunger makes food taste very good!

Anorexia: Focus is Weight

Anorexics care about losing weight.

Calorie restriction, exercise, diet pills, binging, caffeine … any means possible is used in pursuit of this goal.

Anorexics care only about losing weight.

Calorie Restriction: Focus is Calories

CR practitioners care about limiting calories, regardless of weight gain or loss. Some CR practitioners don't lose any weight at all, others lose a little, still others lose a lot. As with all diets, each unique body and metabolism responds uniquely to the food it consumes.

But the focus of CR is not on weight gain or loss. The benefits of the CR are reaped regardless of changes in weight.

Calorie Restriction is just that: limiting caloric intake based on research showing that by limiting an animal's calories it may be possible to increase its lifespan. Research has already shown that this is true for some animals. CR practitioners are hoping to show that it is true for humans as well.

Anorexia: Never Be Seen Eating

Anorexia is a secret, shameful state of mind; and for an anorexic eating is the most repulsive indulgence.

To the anorexic mind eating is evidence of failure, weakness, and one's despicability. It is one thing to know privately that you are all these things, but the idea of letting others actually see you indulging in the loathsome act is intolerable.

Anorexics -- those who eat at all -- do so in secret and shame.

Calorie Restriction: Happy To Be Seen Eating

Most CR practitioners are in fact eager to share the mechanics and efforts involved in eating the CR way. For some, showing how and what they eat helps to fend off the worries or insensitive comments of uninformed family and friends. Some CR practitioners eat family-friendly CR meals; others are in families where different members practice different "flavors" of calorie restriction.

Recently there has been a flurry of television, newspaper, and magazine stories on CR and CR personalities. CR practitioners are generally proud of what they're achieving and look forward to talking about it in public and sharing how they prepare and eat their meals.

Anorexia: Nutrition Doesn't Matter

Anorexics don't worry about nutrition. For an anorexic the only thing that matters is losing weight.

Anorexics starve themselves to death; and those who do eat at all choose only based on the low or lack of calories, never nutrition. Diet breath-mints, sugarless gum and no-calorie sodas are "food" for the anorexic.

Calorie Restriction: Good Nutrition

Calorie Restriction is about restricting Calories only, and, at that, only carefully and moderately. It is not about restricting food! This is why Roy Walford originally called the diet the "High-Low Diet": high all nutrients except calories. What CR practitioners care about is getting the most "bang for the buck" from the foods they eat.

The focus of CR is on getting all an individual's nutrient requirements from the fewest number of calories.

The focus of Calorie Restriction is health and longevity.