EAT THIS

The grapefruit diet revisited

Posted Jan. 21, 2013, at 11:10 a.m.
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If you’ve ever fallen into the “I’ll try anything to lose weight” trap, chances are you’ve tried the grapefruit diet at one time or another. If you’re lucky enough to not be familiar with the Grapefruit Diet, it is believed to have been around since the 1930s. Despite its name, it isn’t about just eating grapefruit. The premise of the diet is that eating grapefruit, along with protein, triggers your body to go into a fat-burning mode that results in rapid weight loss. Some versions of the diet promise that you’ll lose 10 pounds in 12 to 14 days.

A sample of the grapefruit diet menu could be: ½ grapefruit, eggs, bacon and black coffee for breakfast; a salad with dressing for lunch with ½ grapefruit and an unlimited amount of protein, for dinner ½ grapefruit with your choice of any non-starchy vegetables, more protein (meat or fish), unlimited in portion, and then a bedtime snack (grapefruit is encouraged). Dieters are encouraged to drink lots of black coffee and water throughout the day.

The grapefruit diet is referred to in the health care world as a fad diet, and expecting to lose 10 pounds of weight in two weeks is unrealistic.

The grapefruit diet also has been called the Hollywood Diet, and in the 1970s it made a big resurgence as the Mayo Clinic Diet, but has no association with the real Mayo Clinic in Minnesota.

The grapefruit diet is based on the premise that grapefruit possess fat-burning enzymes; near-magical powers that promote weight loss. The “magic” is in the half of a grapefruit that you eat before meals combined with the high protein and fat in your meals that produce a metabolic reaction that transforms you into a fat-burning machine.

If you lose weight during the 12-14 days, it is because of your hypocaloric intake, not because of any chemical reaction that occurs when you combine grapefruit with protein foods. But chances are the results won’t last. Most of the weight loss that occurs is going to be from fluid, and the weight will probably come back after the two weeks if you return to your old eating habits. The other problem is that to maintain weight loss long term, eating habits need to be modified, and this doesn’t occur in two weeks.

Early studies of the grapefruit diet suggested that subjects on the diet would lose weight, but this was based on the calorie restriction of the diet rather than any special fat-burning ability of grapefruit.

Some researchers took a look the health benefits of grapefruit beginning in the winter of 2009 trying to answer the question: “Does eating half a grapefruit before each meal decrease weight, blood pressure or cholesterol levels?”

A randomized controlled study was designed in which 74 participants were enrolled in two cohorts separated by a year (winter 2009-2010 and winter 2010-2011). The study corresponded to a seasonal grapefruit crop production and lasted for nine weeks. There was a three-week washout period followed by six weeks of diet intervention. Unfortunately, the study was not blinded, so this introduced the possibility of some bias in evaluating results.

The participants were instructed on how to eat a grapefruit. They were told to eat half the grapefruit before each meal. They were to peel the grapefruit, eat the entire portion including the pith — that white part that most people usually throw away because it tends to be a little bitter. Participants were not allowed to add sugar to their grapefruit, but if they wished they were allowed to use a zero-calorie sweetener.

A registered dietitian collected data about the participants’ dietary intake based on a 24-hour recall. The participants had a logbook in which they kept a detailed record of each time they ate grapefruit during the six-week intervention.

Although the study found that the grapefruit diet didn’t result in weight loss, the grapefruit intervention group did have a decrease in waist and hip circumference and systolic blood pressure. Unfortunately, when compared to the control group, the changes were not statistically significant. Calorie intake in the grapefruit group remained fairly constant, indicating that grapefruit eaten before a meal does not result in fewer overall calories eaten. Each group showed a significant decrease in total cholesterol and LDL cholesterol. LDL in the grapefruit group dropped an average of 18 points, which was a larger change than expected. The cause was believed to be the fiber, but fiber intake in both groups remained fairly constant. The researchers further explained that the fat around the belly, which is thought to be a greater predictor of high blood lipids than body mass index, so the drop in waist circumference is believed to be what triggered the drop in LDL cholesterol.

The subjects in the grapefruit group may not have lost a great deal of weight, but they did lose unhealthy belly fat. They also lowered their LDL cholesterol and their systolic blood pressure. The high level of the antioxidant vitamin C in the grapefruit may have played a role in lowering blood pressure.

Final Thoughts

Grapefruit is a nutritious and tasty fruit choice. I like it with a little salt on it — not sugar. If you enjoy it ,then eat it. Don’t believe, however, that any single food is going to make you skinny. Many fad diets are based on inaccurate information. If they work at all, it is because they restrict calories. Most people are going to lose weight on an intake of only 800 calories daily.

If you are interested in losing weight, the best diet is one that consists of a variety of foods, spreading your calories throughout the day, and including physical activity consisting of at least 30 minutes into your daily schedule.

Georgia Clark-Albert is a registered dietitian and adjunct nutrition instructor at Eastern Maine Community College who lives in Athens. Read more of her columns and post questions at bangordailynews.com or email her at GeorgiaMaineMSRDCDE@gmail.com.

 

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