There are fad diets that emphasize proteins over carbohydrates, or fruits one day with meat the next or eating vegetarian exclusively. All these may have valid elements, but they almost all tend to go too far in one direction or another.

Everyday, at regular intervals, a person interested in optimizing health should eat daily meals consisting of fruits and vegetables, grains, dairy and a protein source. Of course, there will be exceptions for those with special dietary needs. Some people, for example, can’t process dairy products. Others are sensitive to peanuts or other things.

But the four traditional food groups, in the proper proportion, remain the undisputed recommendation of every reputable nutrition scientist. The reasons are that studies continue to support the notion that these supply the compounds needed by the body. From those it can perform muscle maintenance, proper electrolyte balance, cellular repair and other essential activities along with the needed energy to carry out all of them.

Nature, as discovered by science, determines what the body needs – not marketing.

Insoluble fiber, for example, as gained from fruit, vegetables and grains isn’t readily digested. As a result it helps digestion and in cleansing the digestive system.

Certain vitamins (D, B, E, K) and minerals (lithium, calcium, postassium) are needed for carrying out the thousands of biochemical reactions critical to proper health. Sodium and potassium, in moderation, are used by the heart muscle in order to keep pumping blood through the body.

Proteins are needed so the body can lyse (split) them into essential amino acids. Those amino acids are then used to build up new proteins used for muscle and other important components.

Carbohydrates (chiefly those easily converted to glucose) are needed to supply the starting point of the cycle that generates energy to fuel all the other processes. This is a fundamental process called the Krebs cycle that converts sugars into ATP (Adenosine Triphosphate), which is then converted to ADP (Adenosine Diphosphate), releasing energy.

Fad diets can supply many of these essentials, but typically do so in the wrong proportion or with too much at one time, not enough at another. They also frequently contain additional components that are not helpful, and – in excess – may be harmful, such as excessive fats or complex sugars.

In the world of diet, moderation and regularity may not sound glamorous, but it’s the key to good health.

There is the 3-day diet, which touts eating little more than fruits for three days, followed by vegetables or meat or grains the other days. There are lots of variations.

While it’s certainly true that eating fruit regularly is a key element to good health – most contain needed carbohydrates, vitamins and fiber – eating almost exclusively fruit for three days leads to imbalance – in carbohydrates, fiber and additional otherwise healthy components. To an extent the body will equalize and store what it needs for later, but there are limits.

Similarly, the ‘low carb, high protein’ diets, such as Atkins, recommend cutting way down on carbohydrates and eating substantial amounts of food high in protein. Here again protein is vital to proper nutrition, but so are carbohydrates. Putting too much emphasis on the first over the second leads to rapid, temporary weight loss, but at a high cost.

Carbohydrates are essential for supplying energy for all biochemical processes. Though the body, when needed, will use other sources, such as fat and protein. Too great an emphasis on protein reduces the ability of the body to store and regulate the appropriate amount of water, whereas carbohydrates help that.

There are very attractive sounding ‘chocolate diets’. Nearly everyone loves chocolate and, contrary to some reports of a few years ago, it is healthy – in moderation. Chocolate contains anti-oxidants and other compounds that are helpful. But, as with anything, too much of a good thing is just that – too much. Also, since many will seek chocolate in forms that come with high fat, high sugar amounts it’s possible to get some not-so-helpful elements along with the good.

There are ultra-low fat diets. Once again, the problem isn’t with reduced fat, but going to extremes. A certain amount of fat in the diet is a healthy thing.

Any diet which makes promises of radical, rapid or quick weight loss – or any other extreme claim – is almost guaranteed to be more harmful than helpful. The human body has evolved over millions of years and decades of good nutritional research still confirms the common sense truth: balance is good, moderation is healthy.

Eat moderate portions at regular intervals of fruits and vegetables (for vitamins, carbohydrates and fiber), grains (for carbohydrates, vitamins, minerals and fiber), protein (for amino acids) and dairy products (for calcium, unless you’re lactose intolerant). For the average person, between 2000-2500 calories per day is appropriate. Less for women, on average, and for those seeking rapid weight loss.

A balanced diet, coupled with age-appropriate, moderate and regular exercise, will lead to a healthy percentage of body fat, good muscle tone and a well-tuned system. You’ll find you feel better and look good.

But dieting is not without risks, especially in an age when so many fad diets clamor for attention. The desire to lose weight rapidly can lead to health problems that outweigh the benefits of dieting. Rapid weight-loss dieting in particular can lead to a ‘rebound’, defeating the purpose in the first place.

First, what do we mean by ‘diet’ in this context?

No matter what specific weight loss plan one chooses, the basic equation of weight loss can not be eliminated: more calories consumed than burned equals weight gain as the body stores the excess in fat. Conversely, more calories used than taken in leads to weight loss, over the long run.

In a resting state, we burn about 70 calories per hour. In a vigorous hour-long hike we burn about 440 calories. A brisk walk for an hour will use up about 240 calories, jogging nearly 600. But balance that against the average 2,000 calorie per day diet. That shows it can be very difficult to lose weight solely by exercise.

On the other hand, reducing caloric intake means reducing the amount of certain foods and drinks. It may mean an apple rather than a candy bar. It might mean fruit juice instead of that high-calorie cappuccino. The cravings that typically accompany dieting can be hard to quell.

Second, dieting has to be done right to be beneficial. It requires the right weight loss plan.

Too-rapid weight loss from drastic diets leads to a ‘rebound’ effect. All too many dieters know the frustration of seeing hard-to-shed pounds return a few months or a year later. It tends to encourage subsequent overeating as the dieter is motivated to just give up.

Dieting by foregoing needed nutrients presents even more of a health risk. We need a certain amount of unsaturated fats daily to have proper nerve function and hormone balance. Carbohydrates are the body’s basic energy source, which is used to power everything we do from simple movements to life-preserving cellular reactions. Sodium and potassium are vital to proper heart and nerve function.

But there are definite health advantages for an individual who commits to a healthy diet and weight loss plan.

Obesity is a factor in the development of diabetes. It increases the odds of coronary heart disease. It increases stress on bones. It often plays a role in depression. All these are serious health issues and dieting is one of the best ways to combat obesity.

It isn’t mere vanity to want an attractive body, either. An attractive body is one that is fit. That leads to ample energy to carry out whatever goals one wants to pursue. Lack of energy makes it much harder to motivate oneself to complete challenging tasks.

There’s nothing wrong with wanting an attractive form for psychological or social purposes either. Humans are social. It’s appropriate to take pride in having achieved a certain body type, within the limits of what is possible to each of us. It presents an image of self-regard and that psychological self-assessment is a significant factor in basic health.

Done well, taken up as a long-term lifestyle strategy and not as a quick fix, dieting is healthy.

The basic weight loss equation certainly remains valid in this case: using more calories than are consumed results in weight loss. If you don’t take in calories by eating, it’s fairly easy to satisfy that equation. Your body burns 70 calories per hour even just sitting idle on the couch.

But while you may be idle, your body’s systems are not.

First of all, the body – deprived of food – will slow down the metabolism and burn calories more slowly. Weight loss can be sudden at first, but the rate slows very soon thereafter.

At first, it goes after glycogen stored in the liver and converts it to glucose to burn for energy. That energy is used to power all the body’s activities.

When that is used up (to a degree), the body then begins going after the energy stored in the bonds of certain molecules in fat cells. The process is called ketosis and accounts for why your breath sometimes smells like fingernail polish (made with ketones) after hard exercise.

So far, that all sounds good. You burn calories, reduce body fat and lose weight. Exactly what you wanted. But, unfortunately, this isn’t all the body is doing under these circumstances.

Because of the relatively rapid weight loss/calorie burning from this method of ‘dieting’ the body will experience a ‘rebound’ effect. In other words, it will cause you to crave food like crazy. The food you do eat will cause you to put on more pounds than you lost. The body is compensating for a radical deficit.

At the same time, there are serious health risks to simply starving or a long term fast. Going without food for a few hours or even a day isn’t dangerous, though it can be uncomfortable since you’ll get very hungry. But this method causes a number of carefully balanced nutrients to get out of whack.

It upsets the delicate balance of insulin, sugar and a variety of other essential compounds. Apart from regulating energy levels, they influence hormones that regulate the brain and nervous system.

Concentrations of potassium and sodium get out of balance unless you compensate with sports-style drinks, which can be more difficult to adjust in the absence of food. Those minerals are key to regulating the heartbeat, not to mention being found in every cell of the body and the fluid in between where they participate in an enormous variety of vital tasks.

Fatigue, dizziness and difficulty concentrating are only three of the milder symptoms that will result. Dehydration is likely, since much of the fluid we gain is from food, not just liquid. That can easily lead to heat stroke if the weather is at all warm and you are even a little active.

The kidneys will have a more difficult time filtering properly. They clean waste material from the blood, play a role in regulating blood pressure and stimulate the bone marrow to make red blood cells.

The odds of heart attack are increased, brain function suffers,… the list is endless. Even if the fast is ended long before death (at about 4 weeks), serious physical effects would occur.

Instead of fasting, eat a balanced, healthy diet of limited calories – combined with an age and circumstance-appropriate exercise program. That is the surest way to lose pounds safely. Your short term and long term health will be in harmony.

The basic idea of the Zone Diet is to adjust the ratio of carbohydrates: proteins: fats to 40:30:30. This means that 40% of calories consumed should be in the form of carbs, 30% from proteins and 30% as fats. Some studies suggest that 30% of proteins is far higher than is healthy for some individuals, particularly those with kidney ailments. The American Heart Association recommends about 10%.

Like the South Beach Diet, one important goal is to adjust insulin levels. But it goes beyond this in attempting to achieve a well-balanced hormone system in general.

One reason is the view that excess insulin production tends to cause the body to convert carbs to stored fat, contrary to most dieter’s goals. By contrast, proteins help stimulate the release of glucagon, which stimulates the liver to shed stored carbs. That in turn leads to a feeling of satiation and a person naturally stops eating, according to the theory.

Unlike South Beach, however, there is a strict emphasis on calorie counting. No more than 500 calories should be consumed during any meal, and no snack with more than 100 calories should be eaten between meals. Balancing carb intake with 3-4 ounces of proteins helps achieve that desired glucagon-insulin balance.

The Zone Diet emphasizes eating fresh vegetables and fruits throughout the dieting period. Nuts, leafy greens and mono-unsaturated fats are preferred. Meals are consumed on a regular schedule, with breakfast consumed within an hour of waking. Carbs from fruits and vegetables are preferred over those from starchy foods like potatoes and pasta.

Alcohol is allowed, but it’s recognized as high glycemic, high-sugar carbohydrates. So, a 4-oz glass of wine would require a trade-off for a ‘block’ of food carbs (36-40 grams). Coffee is discouraged, since it is a stimulant that causes insulin resistance. Water is the beverage of choice in the Zone Diet.

Still, no specific food or drink is expressly forbidden. The idea is to achieve a balance in order to regulate hormone levels. Like any diet, it will need to be adjusted to a particular individual’s circumstances and needs.

The net result of following the diet, according to practitioners, is the desired weight loss while maintaining healthy nutrition. Many report that any cravings disappear in a couple of days. It’s often recommended for those with diabetes by some nutritionists, since it works to adjust insulin levels.

As with any new diet, seeking the advice of your physician is wise. He or she can help you tailor the Zone Diet to your specific situation.

The Glycemic Index

The GI is a measure of the relative amount of blood sugar created in response to consuming carbohydrates. Different carbs metabolize at different rates and slowing the absorption of sugars is one way to shift insulin levels, which play a role in storing excess calories as fat, according to South Beach Diet inventor Dr. Agatston, a Florida cardiologist.

The basic equation – more calories used than consumed leads to weight loss – still holds. But this approach to dieting and weight loss attempts to shift how those calories are used.

Phase 1

In Phase 1 of the South Beach diet, which lasts exactly two weeks, the focus is on shifting from high fat carbs to low fat carbs, such as from fatty cuts of beef to boiled ham. It also attempts to reduce starches such as bread and potatoes, moving instead to foods such as pinto beans and black eyed peas. Sugary soft drinks are eliminated completely. No beer or wine is allowed during this period.

The idea is to adjust the body’s cravings away from high sugar-content, high-fat content foods. This, according to the theory, helps flip the body’s ’switch’ that causes us to store fat. When the switch is on we may crave certain foods, but after ‘retraining’ those cravings disappear gradually.

Portions remain at normal sizes however, and there’s no concentration on counting calories. That makes it simple to develop lists of allowed and forbidden foods to eat during these two weeks.

Phase 2

In Phase 2 some of the rules are relaxed a little. Certain formerly forbidden foods may be consumed. Pasta and bread, in moderate quantities, are back on the ‘Allowed’ list. Dieters can choose from a wide range of foods, such as rice, cereal, fruit and more. The allowed foods to emphasize should be those with a low-GI index. Red wine is re-introduced, again in moderation.

This period lasts as long as needed to achieve the individual dieter’s weight loss goal. For some that may be only a few weeks. For others, it may require several months or more.

Phase 3

Once the weight loss goal is achieved, it’s important to be able to keep those pounds off. Many dieters become frustrated because they see hard-to-lose pounds come sliding back on over time. Phase 3 represents a lifelong commitment to a change in eating habits that will help retain that hard-won goal.

The emphasis is on ‘good’ carbs versus ‘bad’ carbs, as well as choosing ‘good’ over ‘bad’ fats. Good, here, means low GI, bad is high-GI. High fat meats are still discouraged, except as an occasional indulgence. Refined sugars are a no-no. Fiber, to slow digestion of carbs, is considered good, as is eating foods with ample Omega-3 fatty acids, such as fish.

Summary

The South Beach Diet can be put in the category of ‘low carb’ but the emphasis is more on the type of carbohydrates than the amount contained. As with any major diet change considered, consulting your physician before starting is always wise.

No single dieting method is perfect for everyone. But low carbohydrate diets help lower the one thing that all good diets aim at: reduced calories. There’s no getting around the fact that more calories consumed than used leads to weight gain. Reducing carbs the right way can ‘cut to the chase’, nutritionally speaking.

A carbohydrate is just some combination of carbon, hydrogen and oxygen. They’re consumed in the form of sugars or starches. A sugar is a relatively simple carbohydrate. Starches are considered complex carbohydrates.

Far from being harmful, carbohydrates are the body’s primary energy source. That makes them essential. But in modern society, some people get too much potential energy, which turns into real body fat. Any excess calories the body acquires are stored mostly in the chemical bonds in fat cells.

But low carb does not mean no carb. Even the most extreme low carb diets recommend that no less than 40% of calories should come from carbohydrates. Most are in the range of 45-65% depending on the individual. Some people simply process carbs more efficiently than others. At the high end of the range, about 10% should be sugars, 55% complex carbs.

Those considering a low carb diet also sometimes believe it necessarily recommends no fruit or vegetables. Fruits like apples and oranges, it’s true, are often high in sugars. Many vegetables are very starchy. But here again low carb does not mean no carb. A healthy, balanced diet, even while focusing on reducing carbohydrates, will include some fruits and vegetables.

One of the big advantages of a low carb diet is that it doesn’t spend too much time counting calories. The focus, instead, is on adjusting the percentage of certain types of foods eaten. In particular, things like pasta and bread are reduced, sometimes considerably.

But that can lead to a problem, because the bottom line is calories consumed vs calories used. Reducing carbohydrates doesn’t just reduce calories from that source. It alters the way the body uses them, tipping the scales. As with any diet, it’s necessary to observe the results. A healthy diet, even one that aims chiefly at weight loss, should not leave you feeling low on energy all the time.

The way out is simply to adjust according your specific body’s responses. It may mean abandoning the low carb diet approach entirely. It isn’t the perfect choice for everyone.

Some who consider this approach worry about not getting enough fiber. Since fiber contains carbohydrates (technically, it is a carbohydrate), it may need to be reduced. But no responsible low carb diet recommends eliminating fiber entirely.

More importantly, fiber – because of its unique properties – is not digested, at least not fully. That’s part of its usefulness in the diet. So, since it isn’t digested it doesn’t contribute to the body’s amount of calories consumed. It aids digestion and health in many ways, but not by adding to the ‘energy store’. No need to forego fiber.

Investigate the different types of low carb diet and find out if one of them is right for you.

But there is nevertheless ample evidence that a low fat diet can be a great boon to those seeking weight loss and good health in general.

Eating fat doesn’t make you fat. In fact, certain fats are essential to good health. Fat is necessary for proper nerve function, hormone production and other vital processes. About 30-35% of the diet should consist of fats. But not just any fats, only those of a certain type.

Trans-fats raise the level of ‘bad’ cholesterol – LDL (Low Density Lipoproteins). At the same time they lower the ‘good’ type of cholesterol, HDL (High Density Lipoproteins). The good type is essential for proper brain function, just as one example. By contrast, a high ratio of LDL to HDL is a contributor to the risk of heart disease. LDL builds up in the arteries, hardening them and making them more narrow. Trans fat calories should be no more than 1%.

Saturated fats have similar effects. They raise the level of LDL, which leads to the same problems for arteries and blood pressure. They should be limited to no more than 7% of calories.

Monounsaturated fats, by contrast, are those that actually help the body perform those needed functions without contributing to the problems caused by the other two types.

It’s still true, though, that a high fat diet, even the ‘good’ kind, can have a number of drawbacks.

A gram of fat produces 9 calories during digestion. By comparison, carbohydrates and proteins produce only 4 calories per gram. That makes fat ‘energy dense’. And the basic calorie equation remains true: more calories consumed than used leads to weight gain. Therefore, one of the easiest ways to reduce calorie intake is to consume less fat.

Choosing meats that are low in fat and reducing regular milk consumption are two good ways to implement the plan. Certain nuts, like cashews and peanuts, are also high in fat and should be consumed sparingly.

That will help achieve a goal of no more than 65 grams of fat per day based on a 2,000 calorie per day diet. That is equivalent to getting no more than 30% of total calories per day from fats. Those on a very restricted calorie diet (say, 1200-1500 for women and 1600-1800 for men) will want to reduce the amount accordingly.

Keep in mind that every person has individual nutritional requirements. Guidelines appropriate for a middle aged adult seeking to shed a few pounds may not be right for a teen. Any time you consider substantial changes to diet, consulting with your physician first is wise.

A good exercise program is one of the twin pillars that can help reverse that trend. Along with the increased consumption has come a decrease in the amount of exercise the average person gets today. More time at the computer and a host of other reasons are responsible.

But the right diet is the other pillar that is a must. A ‘must’, that is, if the goal is optimal weight and body fat percentage, an attractive appearance, self-esteem and overall health. It isn’t mere vanity that prompts millions to seek that diet. They know, most having tried to diet at one time or another, that many real benefits follow.

Dieting is about more than just losing weight. It’s just as much about achieving optimal nutrition. It’s about creating the body image that you feel comfortable with. It’s about achieving your unique optimal weight range.

Note that important phrase ‘weight range’. No exact number represents your ideal weight. It will fluctuate slightly from week to week. What that range is depends on your BMI (Body Mass Index), your waistline and where you store fat, your natural body type and other factors.

BMI is just your weight (in kilograms) divided by your height (in meters) squared, or BMI = Weight / (Height x Height). To find your weight in metric units, just divide by 2.2, to find your height in meters, multiply inches by 2.54 and divide by 100.

So, suppose you are a woman 5 feet 6 inches tall, weighing 140 lbs. So, (66 inches x 2.54)/100 = 1.676 meters. Your Weight = 140 / 2.2 = 63.6 kg. Therefore, your BMI = 63.6 / (1.676 x 1.676) = 22.6, which is right in the middle of the normal range. See the full table and a BMI calculator here:
http://www.consumer.gov/weightloss/bmi.htm

But a woman 5 feet 6 inches who weighs a 140 pounds may still feel the need to diet. It’s not then strictly just a health issue. She may want to feel more attractive. She may legitimately believe that a slimmer physique or one with more muscle will give her more energy.

Or, she may not. That’s where self-image plays a significant role. She may adjust her body, or her attitude, or both. Or, she may be perfectly satisfied with herself as she is.

Part of that outlook will (and should) depend on age and personal circumstances. If that same woman is 26 she may feel the need to shed a few pounds in order to achieve her personal goal. If she’s 16, she likely has a few years of growth left and the whole situation will sort itself out with time. If she’s 56, she might be very pleased that she is in a healthy range and not pay much heed to other factors, but still want to diet to achieve optimal nutrition.

Personal situations count heavily when deciding whether or not to diet.