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True or False – Eating more slowly results in consuming fewer calories

Posted on December 18, 2012

True.

The trend in our society is to do everything in a hurry and many Americans report that they feel rushed on a daily basis. Regretfully, this often carries over to our nutritional practices as well. I read recently that Americans now eat 1 out of 5 meals (that’s 20%!) in their cars. I remember, as will many of you, being scolded by my mother for eating too fast. I was the youngest of four boys. Breakfast, lunch, and dinner were by no means times to sit down, talk, and socialize as a family, they were times to eat. I imagine we looked like pigs bellying up to a trough during those meals. At times, I still find myself eating too fast and have also wondered if the speed at which we eat impacts the number of calories we consume. It looks like research is starting to address that very question.

An interesting study conducted by Andrade and colleagues (2008) and published in the Journal of the American Dietetic Association examined number of calories consumed and satiety (the feeling of being full and satisfied after a meal), in participants who either ate a meal quickly (in 8 minutes) or slowly (in 29 minutes). The authors results showed that research participants who ate fast consumed on average 645 calories, whereas those who ate more slowly consumed 579 calories. Interestingly, those participants who ate slower also consumed more water during the meal, 409 grams of water verses 289 grams for those who ate quickly. The slower eaters also rated the meal as more satisfying and pleasant. So, there appears to be a number of benefits to eating slower, though I imagine the scolding I received from my mother for eating too fast came from a fear of choking. One of the reasons we might eat less when we eat slowly is that it takes about 20 minutes for our body to signal itself when it is full. My advice is to slow down, enjoy your food, and you will likely take in fewer calories.

Reference:
Andrade A, Greene G, Melanson K: Eating slowly let to decreases in energy intake within meals in healthy women. Journal of the American Dietetic Association (2008), July 2008, pps. 1186-1191.

Categories: Myths

True or False – Drinking coffee can help prevent Type II Diabetes, Parkinson’s, and Alzheimer’s Disease

Posted on December 10, 2012

True.

I’m very much like 100 million or so other Americans in that I drink coffee on a regular basis. I think we all know someone (like me) who doesn’t function all that well in the morning until about cup number two or three. Much to my dismay, I remember years ago hearing reports of how drinking coffee could increase the risk for cancer and heart disease. There has been a tremendous amount of research conducted on coffee. I recently performed an electronic search through the library for scientific references using the word “coffee” and came up with nearly 23,000 hits. In a nutshell, the thousands of studies conducted on coffee suggest there are far more health benefits related to drinking coffee than there are risks. Taylor and Demmig-Adams (2007) published a review article on the health risks and benefits of coffee drinking. The authors concluded that “The most currently available evidence suggests that coffee drinking can help reduce the risk of several diseases, most notably type 2 diabetes, Alzheimer’s disease, and Parkinson’s disease, although the underlying mechanisms for this effect are still being investigated”. Other review articles have come up with very similar conclusions. Other studies also suggest that drinking coffee can help reduce the risk of certain cancers and even heart disease. One of the reasons coffee may be beneficial for health is that it is loaded with antioxidants. Antioxidants are molecules that help prevent healthy cells in our body from being damaged. Even with all the benefits of coffee, there can be a downside to drinking it. For some, coffee can cause the jitters or the shakes, can increase heart rate, and can result in higher levels of anxiety or nervousness. Also, those who are pregnant, have hypertension, are at risk for osteoporosis, or have epilepsy should talk to their doctor about drinking coffee.

Reference:
Taylor S & Demmig-Adams B: To sip or not to sip: the potential health risks and benefits of coffee drinking. Nutrition & Food Science (2007), Vol 37, pps. 406-418.

Categories: Myths

True or False – Eating carrots improves your vision

Posted on November 30, 2012

False.

Proposed links between certain foods and improved eyesight have been discussed for hundreds and maybe even thousands of years. When the focus is improving eyesight, carrots usually dominate the conversation. Many mothers and fathers have told their children to eat their carrots because it would improve their eyesight, especially in the dark. Truth be told, there is little to no evidence supporting the idea that eating carrots leads to better vision. Supposedly this myth originated during WWII when Britain’s Air Ministry pilots started shooting down more Nazi bombers at night. The pilots were relying on a new technology in their war efforts, Airborne Interception Radar, but the Air Ministry didn’t want the Nazi’s to know that. To keep their secret safe, they purposely spread a rumor that their pilots’ improved vision was due to eating tremendous amounts of carrots. Carrots are high in vitamin A, which is important for good eye health; however, vitamin A deficiency is relatively rare in industrialized nations. Authors of one study (Smith et al., 1999) asked people about carrot consumption and seeing in the dark. Surprisingly, they found that women in their study who said they ate more carrots reported higher rates of poor night vision. It’s not likely that eating carrots negatively impacted vision in these women, but as the authors state “it is probable that people attributing poor driving ability to their vision may be eating more carrots in the hope of reversing this decline”. My wife and I have both had Lasik eye surgery so we wouldn’t need to wear contacts or glasses. If we thought we could have improved our vision by eating carrots that would have been the first thing we would have tried!

Reference:
Smith W, Mitchell P, Lazarus R: Carrots, carotene and seeing in the dark. Australian and New Zealand Journal of Opthalmology (1999), Vol 27, pps. 200-203.

Categories: Myths

True or False – Eating turkey makes you drowsy

Posted on November 19, 2012

False.

You slowly push yourself away from the table after having just completed your third heaping plate of Thanksgiving dinner. The meal included mashed potatoes, gravy, stuffing, cranberry sauce, three bean salad, homemade bread, pumpkin pie, ice cream, wine, and of course lots of turkey. You slosh your way over to the sofa where you settle in and get comfortable. Your intention is to watch some Thanksgiving Day football. However, even with nearly a dozen kids running crazy through the house rambunctiously reenacting scenes from Star Wars, you drift off to sleep in a matter of minutes. An hour and fifteen minutes later, after getting struck by a misguided light saber strike, you wake up and realize you missed the entire fourth quarter of the game. Of course the blame for drifting off into the dream state is immediately directed at the turkey, which we all know is laced with that evil substance tryptophan. Tryptophan is an amino acid and is a precursor (helps make) serotonin.

Serotonin can be converted or turned into melatonin which has been shown to cause sleepiness and drowsiness in humans. Research has shown that giving humans L-tryptophan (Charney et al, 1982) can increase feelings of drowsiness. However, it is widely believed that tryptophan doesn’t act on the brain unless it is consumed on an empty stomach and there is no protein present in the gut (there is lots of protein in turkey). Additionally, there is not enough tryptophan in turkey to cause you to become sleepy. There is also tryptophan in eggs, beans, cheese, beef, pork, lamb, chicken, milk, barley, brown rice, fish, and peanuts, yet none of these foods are credited, or blamed for inducing sleep. Experts agree that one of the reasons we become sleepy after we eat a big meal is blood is diverted from the brain and other parts of the body to the stomach to aid with digestion.

Reference:
Charney D, Heninger G, Reinhard J, Sternberg D, Hafstead K: The effect of intravenous L-tryptophan on prolactin and growth hormone and mood in healthy subjects. Psychopharmacology (1982), Vol 77, pps. 217-222.

Categories: Myths

True or False – Frozen fruits & veggies are usually as nutritious as fresh ones

Posted on November 14, 2012

True.

There is no question that consuming more fruits and vegetables in our diets results in a variety of positive health benefits. It is recommended that we consume between 8 and 10 servings a day, but in reality most adults consume between 2 and 4 servings. Freezing fruits and vegetables for resale started to occur on a large scale basis in the mid to late 1920’s, and articles written on the health aspect of these products started to appear in the early 1930’s. When many people think of “fresh” fruits and vegetables they think of what they see and buy in grocery stores. In reality, the produce sold in grocery stores may not be that fresh. Consider that produce must be picked (often before it is ripe), then sometimes stored for a day or two, transported (sometimes for thousands of miles) to a grocery store where it again might sit in storage for a day or longer.

Sometimes chemicals are added to produce to finish the ripening process, and then it is placed on the shelf for purchase, where again it might sit for a day or longer. This entire process can easily take 1 to 2 weeks and can lead to significant nutrient loss. In contrast, frozen fruits and vegetable are often picked at their peak of ripeness (the time when they are most nutrient packed) and frozen within hours, theoretically locking in many of those nutrients. One study which examined antioxidants in fresh and frozen vegetables was published in the Journal of Food Science (2008). The authors concluded “the assumption that frozen vegetables have a lower antioxidant potential than fresh ones is not a universal truth, but depends on the vegetable considered” and “frozen cooked vegetables often present a higher antioxidant activity than the corresponding fresh ones”.

Reference:
Danesi F & Bordoni A: Effect of home freezing and Italian style of cooking on antioxidant activity of edible vegetables. Journal of Food Science (2008), Vol 73, pps. H109-H112.

Categories: Myths

True or False – Breakfast should be your largest meal of the day

Posted on October 22, 2012

False.

This is another one of those myths that sounds logical when you think about it. Eat your largest meal in the morning and all those calories will be “burned” off as you go about your daily business. However, it is not true. Our bodies’ burn calories breaking down and absorbing the food we eat. This is called diet-induced energy expenditure and is responsible for about 10% of the calories we burn every day. This idea of having breakfast be your largest meal has been around for sometime and is still popular today, you’ve likely heard the saying eat breakfast like a king, lunch like a prince, and dinner like a pauper. Well, not everyone likes eating breakfast, especially a huge breakfast! This eating pattern is sometimes referred to as the reverse diet because for most people, dinner is their largest meal of the day. I could find no scientific evidence that showed the number of calories we use to digest and store food is any different for food eaten early in the morning, during the middle of the day, or late at night. Actually, Taylor & Garrow (2001) reported that neither the number of meals we eat during the day, nor a morning fast had an impact on energy expenditure. Research does show that skipping breakfast and consuming more calories later in the day is related to obesity. However, there is not a cause and effect relationship between these two variables. Skipping breakfast doesn’t “cause” you to become obese. Maybe those who skip breakfast overeat at other meals, or aren’t as active as individuals who consistently have breakfast. Keep in mind, weight loss or weight gain comes down to the simple equation of calories in vs. calories out.

Reference:
Taylor M & Garrow J: Compared with nibbling, neither gorging nor a morning fast affect short-term energy balance in obese patients in a chamber calorimeter. International Journal of Obesity (2001), Vol 25, pps. 519-528.

Categories: Myths