The Promise

It's a pitch Hollywood celebs love: that the alkaline diet -- also known as the alkaline ash diet or alkaline acid diet -- can help you lose weight and avoid problems like arthritis and cancer. The theory is that some foods, like meat, wheat, refined sugar, and processed foods, cause your body to produce acid, which is bad for you.

So, according to the "science" behind this diet, eating specific foods that make your body more alkaline can protect against those conditions as well as shed pounds. The alkaline diet really rocketed into the news when Victoria Beckham tweeted about an alkaline diet cookbook in January 2013.

What You Can and Can't Eat

Most fruits and vegetables, soybeans and tofu, and some nuts, seeds, and legumes are alkaline-promoting foods, so they're fair game.

Dairy, eggs, meat, most grains, and processed foods, like canned and packaged snacks and convenience foods, fall on the acid side and are not allowed.

Most books that tout the alkaline diet say you shouldn't have alcohol or caffeine, either.

Level of Effort: High

You'll be cutting out a lot of foods you may be used to eating.

Limitations: Many foods are off-limits, and so are alcohol and caffeine.

Cooking and shopping: You can get fruits and vegetables at the grocery store. It may take a while to learn how to prep and cook your meals when you use fresh foods.

In-person meetings: No.

Exercise: Not required.

Does It Allow for Restrictions or Preferences?

Vegetarians and vegans: This diet is mostly to become completely vegetarian. It also works for vegans, in that dairy is off-limits.

Gluten-free: The diet excludes wheat, but to avoid gluten completely, you'll need to check food labels carefully, as gluten is not just in wheat.

Besides wheat, the diet nixes most of the other major triggers for food allergies, including milk, eggs, peanuts, walnuts, fish, and shellfish. It's also good for people who are trying to avoid fat and sugar.

What Else You Should Know

Cost: Many websites with information about the alkaline diet also sell courses, books, supplements, and alkaline-infused water, food, and drinks. You do not need to buy these things to follow the alkaline diet. There are many free alkaline food charts online that list foods you can buy at the grocery store.

Support: This is a diet you do on your own.

Does It Work?

Maybe, but not for the reasons it claims.

First, a little chemistry: A pH level measures how acid or alkaline something is. A pH of 0 is totally acidic, while a pH of 14 is completely alkaline. A pH of 7 is neutral. Those levels vary throughout your body. Your blood is slightly alkaline, with a pH between 7.35 and 7.45. Your stomach is very acidic, with a pH of 3.5 or below, so it can break down food. And your urine changes, depending on what you eat -- that's how your body keeps the level in your blood steady.

The alkaline diet claims to help your body maintain its blood pH level. In fact, nothing you eat is going to substantially change the pH of your blood. Your body works to keep that level constant.

But the foods you're supposed to eat on the alkaline diet are good for you and will support a healthy weight loss: lots of fruits and vegetables, and lots of water. Avoiding sugar, alcohol, and processed foods is healthy weight-loss advice, too.

As to the other health claims, there's some early evidence that a diet low in acid-producing foods like animal protein (such as meat and cheese) and bread and high in fruits and veggies could help prevent kidney stones, keep bones and muscles strong, improve heart health and brain function, reduce low back pain, and lower risk for type 2 diabetes. But researchers aren't sure of some of these claims yet.

People who believe in the alkaline diet say that though acid-producing foods shift our pH balance for only a little while, if you keep shifting your blood pH over and over, you can cause long-lasting acidity.

Is It Good for Certain Conditions?

Following an alkaline diet means choosing fruits and vegetables over higher-calorie, higher-fat choices. You will also shun prepared foods, which often have a lot of sodium.

Thats great news for heart health because these steps help lower blood pressure and cholesterol, which are big risk factors for heart disease.

Getting to a healthy weight is also important in preventing and treating diabetes and osteoarthritis.

Some studies have found that an alkaline environment may make certain chemotherapy drugs more effective or less toxic. But it has not been shown that an alkaline diet can do this or help prevent cancer. If you have cancer, talk to your doctor or dietitian about your nutritional needs before starting any type of diet.

The Final Word

The emphasis on fruits and vegetables that is at the core of alkaline diets offers the promise of healthy weight loss. No special gear or supplements are required.

Youll have the best success with it if you like to choose and experiment with new foods and love to cook.

But following an alkaline diet will be tough for many people.

A lot of favorite foods that are allowed in moderation in other plans (including lean meat, low-fat dairy, bread, and sweets) are forbidden here. Protein is limited to plant-based sources such as beans and tofu. This means you will have to make sure you get enough protein and calcium.

Eating out also can be a challenge. If you travel a lot for work or have a busy schedule, you might feel bogged down by all the food selection and prep.

Finally, many alkaline diets fail to address a major factor in weight loss and wellness success: exercise. You should include fitness in any healthy eating plan that you choose. The American Heart Association and the CDC recommend getting at least 150 minutes of exercise each week. If you have any medical problems or are out of shape, talk to your doctor first.