As we start to turn the corner from wintertime and head into spring, many of us start thinking about how we are going to “spring clean” any extra accumulation from the winter. As we start sweeping out the dust bunnies under the bed, we may also start thinking about how to lose the few extra pounds we have accumulated during the cold months. Because it is still wintertime we do still need to focus on support of our internal energy production; (for more on this, see Conserving) but this is possible to do while also starting to increase the body’s metabolism in preparation for the warmer months.
In my 12 years of seeing patients, I have encountered many diet regimens; my patients have come in zoning, flushing fat, south beaching, low fat, high fat, vegan, high protein and everything in between. But one diet that seems to have persisted over time is the grapefruit diet: basically, eat grapefruit at the beginning of every meal, limit your calorie consumption to less than 800 per day, and the grapefruit will burn the fat right off of you. So let’s take a moment and talk about whether this is a good regimen and whether grapefruit can play a role in weight loss.
First I’ll talk about the second half of the grapefruit diet: Any long-term regimen that recommends less than 800 calories per day will probably aid in weight loss at the outset. That said, after a week or two the body will reset its metabolism and go into starvation mode. The effect of this is that you will stop being able to lose weight by restricting calories and your metabolism will still be lowered once you return to your normal caloric intake causing rapid weight gain. Also, when you lose weight rapidly in combination with low levels of food in the bloodstream, your body can go into ketosis, which is dangerous for the health of the brain. Also, if you are burning fat quickly you can release stored toxins into the blood very quickly; especially for those who already have other health conditions this can make you feel downright nasty. So, I’m not an advocate for the severe caloric restriction part of the plan.
So now, let’s talk about grapefruit. There are studies that indicate that eating grapefruit at the beginning of each meal will help you eat less and lose weight. One study, however, compared this to drinking a glass of water or any high density low calorie substance and didn’t find much difference; the point here is that your stomach is full before you start eating the high-calorie stuff. That said, those people who had grapefruit rather than water developed better blood cholesterol levels over time.
Another study compared people taking grapefruit either in whole, juice, or capsule form against those taking a placebo capsule. Those eating whole grapefruit lost the most weight, but all three groups had a statistically significant weight loss greater than those who took the placebo. This does indicate that the grapefruit itself can accelerate weight loss. Also, those who were taking grapefruit had lower levels of insulin in their bloodstream following a meal, and showed improvement in insulin resistence (which can lead to type 2 diabetes).
One interesting study done on mice just looked at the effect of inhaling the scent of grapefruit oil. This study found that inhalation of grapefruit oil scent helped to excite the sympathetic nerves, reduce appetite, and increase fat burning. They then blocked their sense of smell, and inhalation of the oil without being able to sense the scent showed no effect. This indicates that having your brain register the scent of grapefruit in itself may help with weight loss over time.
Overall, grapefruit does seem to be a useful adjunct to a weight loss plan. It can possibly help burn fat, improve insulin and cholesterol levels, and replace unwanted extra calories by filling you up at the beginning of your meal. So eat reasonably, and enjoy this tasty late winter delight to help boost metabolism and get ready for the warm weather to come!