No doubt you've seen the claims: "4,000 percent more potent than creatine monohydrate!"

In fact, so many far-fetched claims have been made for supplements in recent years—particularly the ones that help you build muscle and lose body fat—that many people have come to believe that all supplements are just expensive forms of snake oil. Others echo medical professionals who implore people to get their nutrients only from real food.

It isn't a bad idea to look to food first for your nutrients. The problem is, few people eat a large enough variety of foods to meet all nutritional requirements. Dieters limit or eliminate foods that contain vital nutrients.

Enter dietary supplements. Although food should always come first, supplements offer an effective alternative for getting nutrients that either aren't available in sufficient quantity in food or are in foods that you may not be eating.

Keep in mind, what's best for one bodybuilder may be entirely unsuitable for another. A trainee who finds it difficult to eat enough food to gain lean body mass could use a quality weight-gain powder but probably not a meal replacement or a basic protein powder.

1. Creatine

Creatine is perhaps the most efficient supplement if you're doing a high-intensity activity, but if your primary exercise consists of aerobics and you're aiming for an increase in work capacity, creatine would be a complete waste of money.

Few supplements have the solid scientific foundation that creatine has. Studies show that it's effective for 80 percent of those who use it. Since creatine is found naturally in meat, the more meat you eat, the less likely you'll need creatine supplementation. Vegetarians or those who rarely eat meat, however, can get huge boosts from most creatine supplements.

Creatine's primary use is as a backup phosphate donor for the replenishment of ATP, the most elemental form of energy and the source of energy for all muscular contractions. In other words, creatine acts like a second battery in your car. It's also a buffer, helping neutralize the acidity that blunts energy production in trained muscle.

The major controversies regarding creatine are its side effects and the best form to use. Nearly all side effects attributed to creatine, such as muscle cramps, kidney disease and gastrointestinal disturbances, haven't proved significant under controlled scientific scrutiny. Although various claims are made for a variety of creatine supplements, creatine monohydrate, which is 99 percent absorbed, is the best form to use.

By the way, the level of creatine in the blood is meaningless. What counts is how much gets delivered to muscle, which is controlled by the so-called creatine transport protein. It's activated by the sodium/potassium pump mechanism, which in turn is activated by insulin.

Recent studies show that combining creatine with a fast-acting protein, such as whey, enable you to get the benefits of increased creatine uptake without having to eat a lot of simple carbs.

2. Casein-Whey Protein Supplements

Milk protein consists of 80 percent casein and 20 percent whey, and that's the best combination for promoting a positive nitrogen balance in bodybuilders. That's because casein is a slow-acting protein that delivers its amino acids over a period of seven hours, and whey is a fast-acting protein, peaking in 90 minutes.

The faster a protein is absorbed, the faster the liver oxidizes its amino acids. That sounds bad, but whey's rapid delivery of amino acids also favors increased protein synthesis. A longer-acting protein, such as casein, prevents the excess breakdown of protein, an anticatabolic effect, which ultimately promotes an anabolic effect - growth.

Besides the high-quality protein content of casein/whey, the newer formulations have little or no lactose (i.e., milk sugar), which some people have negative reactions to. The native milk proteins also provide a host of smaller proteins called peptides, many of which, such as lactoferrin, have vital health benefits. The rich cysteine content of whey acts as a precursor of glutathione, a primary endogenous antioxidant and liver detoxifier in the body.

3. Omega-3 Fatty Acids

If you don't eat fatty fish at least three times a week, you'll be deficient in omega-3 fatty acids. Studies suggest that's the case with about 80 percent of people. Since the brain is composed of 40 percent DHA, one of the omega-3s, a long-term lack may cause aberrations in brain neurotransmitter function, resulting in depression and aggression.

Omega-3s provide numerous health benefits. Recent studies show that middle-aged people who eat diets rich in omega-3 fats have a 75 percent decreased incidence of Alzheimer's disease. Omega-3s help prevent several types of cancer, including breast and prostate cancers.

They improve insulin sensitivity and make cellular membranes more pliable so that hormones can more efficiently interact with cellular receptors. Some studies suggest that a generous intake of omega-3, at least five grams daily, blunts body fat synthesis and reduces inflammation, which can help relieve sore joints and muscles.

You should know that there's an initial inflammatory feature of muscular hypertrophy, or growth that can be blunted by omega-3 fats and other drugs. The solution is simply not to take omega-3s before training.

The liquid form of omega-3 supplements is preferred because of less "backup" after swallowing and because it takes so many capsules to give you the five-gram dosage. Capsules will do if you can stand to swallow them.

4. Antioxidants

The term 'antioxidant' is an umbrella word encompassing thousands of nutrients, including vitamins, minerals, and flavonoids. Many are found in fruits and vegetables, which are often not included in sufficient quantity in typical bodybuilding diets, especially fat-loss diets.

Exercise produces oxidative reactions that would normally be toxic to your body. The body's antioxidant systems that work against oxidation are often overwhelmed by exercise. Supplemental antioxidants help them deal with numerous toxic oxidants, such as the free radicals produced when exercise pumps up your oxygen metabolism.

Don't fall prey to alarmist studies that not only decry the health value of dietary antioxidants, such as vitamin E, but even allege that they're harmful. The truth is that all antioxidants work as a team. When neutralizing an oxidant, an antioxidant is often temporarily converted into an oxidant itself.

Other antioxidants, however, donate an electron that converts the former antioxidant back to its "good guy" status. The studies that find fault with antioxidants always talk about just one antioxidant, which wrongly ignores antioxidant teamwork. Typical dietary antioxidants include vitamins E, C and B-complex, as well as:

• selenium
• zinc
• manganese
• green tea extract
• grapeseed extract

5. Post-Workout Recovery Drinks

Although similar to protein drinks, PWO's also contain simple carbs and other nutrients that good research shows help promote increased muscular recovery and growth. The best protein found in such formulas is whey, which is rapidly absorbed. Simple carbs are added because they promote glycogen replenishment and insulin release.

Studies show that recovery drinks can be used advantageously both before and immediately following training. A drink before training increases amino acid delivery to muscles because of the increased blood flow that exercise induces.

Forget the notion that simple carbs will make you fat or inhibit fat burning. Any carbs taken within 90 minutes of training go directly toward glycogen replacement, with zero spillover into fat.

6. Glucosamine And Chondroitin

Both substances are found naturally in the body. They mollify the pain linked to sore joints and connective tissue and promote healing. The latter effect distinguishes the glucosamine-and-chondroitin combo from anti-inflammatory drugs, which relieve pain but do nothing to help repair tissue or retard further joint destruction.

Reports of side effects linked to glucosamine use, such as interference with normal glucose metabolism, aren't true. They were based on dosages that would never be used by any human. The one thing to keep in mind about glucosamine and chondroitin is that joints have relatively poor blood circulation.

That means it takes time for supplements aimed at joint treatment to work. So plan not to feel anything for about two months after you start using glucosamine. After that, pain control with the supplement is comparable to what happens with drug use, according to various studies. The typical doses are 1,200 milligrams daily of glucosamine and 800 of chondroitin, which can be doubled initially.

7. Multimineral Supplements

It may seem odd to put such a common supplement as minerals on this list, but few people are aware that minerals are enzyme activators. Many vitamins, on the other hand, are coenzymes, which means that without minerals they're useless. Many minerals, such as zinc and chromium, also interact with various anabolic hormones, such as testosterone, growth hormone and insulin.

Since most vitamin-and-mineral combinations have sufficient vitamin content but skimp on minerals, it's prudent to take a high-potency multimineral containing all the ones you need. That's particularly important if you're on a diet that restricts food groups, such as dairy products, which are the best source of calcium.

8. Green Tea

Although green tea is an antioxidant, research on it is so impressive that I chose to list it alone. The active ingredients in green tea are a group of antioxidant compounds known as catechins. The most active catechin goes under the acronym of EGCG, and it's about 100 times more potent in antioxidant activity than vitamins E and C.

Green tea offers many health benefits, such as inhibition of cardiovascular disease and cancer. It also has some mild thermogenic effects, independent of its caffeine content, that may assist fat loss. Some studies even show that green tea offers protection against joint degeneration. If you don't have the time or inclination to drink several cups of green tea daily, you can get the same or better effects by using standardized capsules or tablets of green tea.

9. Over-The-Counter Estrogen Blockers

The last survivors of the pro-hormone supplements, which were removed from sale last January, estrogen-blocking supplements aren't pro-hormones but do inhibit the enzyme aromatase, which converts androgens into estrogens. In normal men that enzyme is ubiquitous, being present in such tissues as muscle, brain and skin. About 20 percent of the free testosterone circulating in the blood is converted into estrogen by way of aromatase.

So blocking aromatase will lead to an increase in testosterone, which translates into increased size and strength. Estrogen is also related to fat storage, especially fat that's subcutaneous, or just under the skin. That means lowering estrogen will also help increase muscular definition, especially with proper diet and training.

The current estrogen-blocking supplements are safe but shouldn't be used year-round, since men do need some estrogen. Estrogen blockers should not be used by women. About one-third of their estrogen production comes from conversion of adrenal androgens into estrogen through aromatase activity.

10. Fiber Supplements

Unless you eat the minimal five servings a day of various fruits and vegetables, you are likely not taking in enough fiber. The popular low-carbohydrate diets are all deficient in fiber. Fiber helps lower total body inflammation and protects against elevated blood lipids and blood pressure.

Soluble fiber (such as guar gum or psyllium) taken just before a meal containing simple or high-glycemic-index carbs will slow the entry of the carbs into the blood. That means less insulin release, less body fat and a stabilized blood glucose level.

Fiber comes in two forms: insoluble and soluble. A cheap and effective source of insoluble fiber is unprocessed wheat bran. Forms of soluble fiber include pectin, guar gum, psyllium and oatmeal. You need both forms to obtain fiber's many benefits.