Pineapple 3-Day Diet

The pineapple diet is based on the Sexy Pineapple Diet, a fad diet created in the 1970s. Since then, many variations of the pineapple diet have been created. One version involves eating just pineapple for three days, while another involves consuming pineapple along with 500 calories of other food.

Read more: 14 Foods to Help You Get Lean

Pineapples are a very healthy fruit that contain a variety of essential nutrients. According to the USDA, a whole pineapple is around 905 grams. A whole pineapple's calories total 453 and are made up of 1.1 grams of fat, 4.9 grams of protein and 118.7 grams of carbohydrates. The majority of these carbohydrates are sugars; there are only 12.7 grams of fiber.

However, this is quite a lot of pineapple ⁠— the equivalent of around 5.5 cups (each cup is roughly 165 grams). The Dietary Guidelines for Americans recommends consuming around 2 cups of fruits each day, as well as 2.5 cups of vegetables.

According to an October 2015 review in the Iranian Journal of Health, Americans only consume around 189 grams of fruit per day, which is less than two-thirds of the recommended amount and barely more than a cup of pineapple.

While you can certainly consume more pineapple, consuming this fruit as your main source of carbohydrates may not provide you with sufficient nutrients. A whole pineapple contains:

• 9 percent of the daily value (DV) for calcium
• 15 percent of the DV for iron
• 21 percent of the DV for potassium
• 26 percent of the DV for magnesium
• 6 percent of the DV for phosphorus
• 10 percent of the DV for zinc
• 111 percent of the DV for copper
• 365 percent of the DV for manganese
• 481 percent of the DV for vitamin C (ascorbic acid)
• 60 percent of the DV for vitamin B1 (thiamin)
• 22 percent of the DV for vitamin B2 (riboflavin)
• 28 percent of the DV for vitamin B3 (niacin)
• 39 percent of the DV for vitamin B5
• 60 percent of the DV for vitamin B6
• 41 percent of the DV for vitamin B9 (folic acid)
• 5 percent of the DV for vitamin K

A whole pineapple also contains small amounts (between 1 and 4 percent of the DV) of other nutrients, like vitamin A, vitamin E and selenium. Pineapples are also rich in bromelain, a protease that can be easily obtained from fibrous parts of the pineapple. According to a December 2014 study in the Journal of Food Studies, pineapples are also rich in antioxidants, though this can vary substantially between pineapple varieties.

If you're following a pineapple diet, you'll be ingesting large amounts of certain nutrients and insufficient amounts of others. Fortunately, consuming excessive manganese, copper and vitamin C are unlikely to harm you at these levels. The National Institutes of Health state that the tolerable upper limits for these nutrients to be quite high, which means that you could theoretically consume two or three pineapples per day without triggering a nutrient-related toxicity.

Exclusively consuming pineapple for three days might help you lose weight, but this weight is unlikely to stay off. According to Harvard Health, women shouldn't consume less than 1,200 calories a day. Men need even more calories ⁠— a minimum of 1,500 calories per day. Anything less than this is likely to be considered a crash diet, which is an unhealthy way to lose weight.

Because pineapple calories total 453 calories per pineapple, you'd likely need to consume multiple pineapples if you were exclusively eating this fruit and trying not to crash diet. Even the liberal version of this diet, which allows people to consume 500 calories from other foods and obtain other essential nutrients, would necessitate the consumption of more than one pineapple.

Other variations of this diet, like the version that asks you to exclusively consume pineapple two days per week and eat whatever you want the other five days of the week, are no healthier than the three-day pineapple diet. Ultimately, any variation of the pineapple diet is probably not your healthiest choice.

Read more: 15 Foods That Help You Peel Off the Pounds

Although a pineapple diet isn't particularly healthy, pineapple is an excellent fruit to incorporate into meal plans. This fruit can have a variety of positive effects on your health, most of which come from its ascorbic acid, fiber and bromelain content. According to a February 2015 study in the International Journal of Nutrition and Food Sciences, pineapple's benefits include:

• Antimicrobial activity
• Antioxidant activity
• Anti-inflammatory properties that can help reduce symptoms in conditions like acute sinusitis, arthritis and gout
• Counteracting nausea and promoting healthy digestion
• Helping maintain good oral health and preventing gum disease
• Preventing urinary tract infections
• Reducing the risk of certain cancers, particularly esophageal, stomach and colon cancers
• Reducing the risk of toxic metal poisoning
• Supporting the formation of collagen (which is found in various parts of the body, including bones, blood vessels, cartilage and muscle)
• Supporting the absorption of non-heme iron
• Supporting male fertility

Despite these varied benefits, this same study cautions against consuming excessive amounts of pineapple. Pineapple is rich in sugar, which can be detrimental to your health in large amounts. The high acid content of this fruit also means that it can irritate your skin, mouth and esophagus.

Essentially, it's possible for pineapple to have some negative effects when consumed in large amounts. Excessive pineapple can even damage your teeth and upset your stomach, triggering gastrointestinal issues like acid reflux.

Read more: The 10 Worst Foods for Acid Reflux

Ultimately, the pineapple is a healthy food that can be beneficial when consumed as part of a healthy diet. According to the review in the Iranian Journal of Health, increasing fruit and vegetable intake can help reduce weight gain and obesity. Consuming pineapple instead of foods with added sugars or processed foods can definitely help support weight loss. Eating pineapple in this way is also nutritionally sustainable and much healthier than a crash diet.