It is estimated that in seven years from now, half of all Americans will suffer from one or more chronic diseases, a majority of which are weight related. The American Medical Association recently declared that obesity itself is a disease. Obesity advocacy groups say that this move will lead to better health outcomes by providing more treatment options, preventative programs and education, as well as better reimbursement for treating individuals fighting obesity.
But what do patients need to know about weight loss? The good news is that a medically healthy weight does not require a very low percent body fat.
Weight loss for health – not for appearance – comes with a different (and in many cases much less demanding) set of recommendations. So for the purposes of this blog post, I’ll focus on key evidence-based advice for patients at risk for weight related disease…
1. You don’t need to lose that much weight to realize substantial health benefits.
A five to ten percent loss of body weight can lower risk for heart disease and other killers. For obese patients, even a modest weight reduction can have significant health benefits. An eleven pound reduction in weight leads to a fifty-eight percent decrease in the chance of developing diabetes. Even just losing two pounds reduces the risk of diabetes by sixteen percent.
2. Most people who succeed at losing weight (and keeping it off) do so with a combination of diet and exercise.
According to the National Weight Control Registry (NWCR) (a database of more than ten thousand Americans who have successfully kept at least 30 pounds off for a year or more):
- Ninety-eight percent of Registry participants report that they modified their food intake in some way to lose weight.
- Ninety-four percent increased their physical activity.
3. Walking is the most common form of exercise reported by successful weight loss subjects.
According to the NWCR, their study participants’ most frequently reported form of activity was walking. That’s not to say that other forms of activity (such as interval and strength training) aren’t an important part of a healthy lifestyle, but it is encouraging to know that brisk walking is a simple, affordable, and easily accessible place to start for most people.
4. Exercise itself (even without weight loss) is one of the most powerful preventive health interventions available.
Physical exercise has been shown to reduce blood pressure; decrease the risk for type 2 diabetes, strokes, certain types of cancer, and heart disease; improve arthritis symptoms and sleep disorders, and reduce erectile dysfunction, anxiety and depression. No pill or procedure can come close to providing all these amazing health benefits.
5. Diet is more important than exercise for shedding pounds of fat.
As I often tell my patients, “You can’t outrun your mouth.” Which means – you can eat far more calories in a short period of time than you can ever hope to burn with exercise. For this reason, diet plays a larger role in weight loss than exercise.
6. It’s more important to lose fat than to lose it by following a particular diet.
If diet is so important for losing weight, the next logical question is “Which diet is best?” Interestingly, the answer may be – whichever one you’ll stick to. Now, of course there are some diets that are more nutritionally sound than others – but the benefits of fat loss are so great, that health benefits are achieved even on relatively “unhealthy” diets. In a landmark diet comparison study, Michael Dansinger showed that study participants achieved similar benefits (such as improved cholesterol profiles, blood pressure, and inflammatory markers) from adhering to any of four vastly different diet regimes ranging from low fat, high carb to low carb, high fat.
7. The healthiest diets limit refined carbohydrate and animal fat intake, while maximizing fruit, vegetable, and healthy fats and protein.
I’ve just argued that a variety of diets work if you stick to them, and adherence is the key to fat loss, and even modest amounts of fat loss can have substantial health benefits. So does it really matter which diet you choose? In the long run, yes. Research has shown that there are some common nutritional principles that result in optimal health. The key ones are:
- Avoid refined carbohydrates as much as possible (such as sugar, fructose, and white flour/rice products). Unrefined carbs (such as whole grains, flax, oatmeal, brown rice, quinoa, berries, and cruciferous veggies) are an important part of a healthy diet.
- Avoid animal fats (trans fats). Healthy fats such as olive, fish and nut oils are preferable.
- Eat a diet rich in fiber, fruits and vegetables.
- Choose lean protein sources, including beans, eggs, chicken, fish, pork, yogurt, and fish.
- Limit alcohol intake and opt for water as your main source of hydration fluid.
8. Aim to lose 1 pound per week.
Cutting out approximately 500 calories from your daily caloric needs (established with a calorie calculator or by personal trial-and-error) is about as much as people can tolerate comfortably over periods of time. Diet adherence decreases as deficits exceed 500 calories per day.
9. The optimal, minimal amount of exercise for the average American adult is about one hour of moderate intensity exercise each day.
There is some disagreement on optimal exercise duration – some groups recommend half an hour per day (American College of Sports Medicine), others (such as the Institute of Medicine) a full hour. A review of the various positions and guidelines is available here. In terms of types of activity, there is general consensus that strength training twice a week should be added to moderate daily aerobic activity for best results.
10. You probably don’t need to take any vitamin or nutrition supplements.
Contrary to popular belief, most Americans (even with their sub-optimal eating habits) meet all of their basic dietary requirements with food intake. Non FDA-approved weight loss supplements have not been found to provide lasting benefits for weight loss and are generally ineffective and sometimes dangerous.
Weight loss drugs and surgical procedures may be effective last resorts for those who have failed to achieve results with diet and exercise. New prescription anti-obesity drugs and FDA-approved over-the-counter options are effective at helping patients shed extra pounds, but often come with unwanted side effects such as anal leakage and adverse cardiac events.
In conclusion, obesity underlies most of America’s chronic disease burden but can be reversed with modest weight loss through diet and exercise modifications. Patient adoption of long-term lifestyle changes are challenged by economic factors (e.g. healthy food “deserts” in inner cities), sedentary lifestyles, poor urban planning, excessive fast food and sugary beverage consumption, increasing portion sizes, and high tech conveniences that reduce energy expenditure, among other factors.
Patients are more likely to begin weight loss programs if recommended to do so by their physician, though studies suggest that they take advice more seriously if their physician is not overweight or obese herself. In our efforts to treat obesity, it may be especially important to lead by example.
A blogger friend of mine referred me to an article about a female runner struggling with gastrointestinal distress. She asked for advice regarding how to prevent the “runner’s trots” and felt fairly mystified regarding its cause. Since up to half of runners face this problem at some point (especially women), I thought I’d post some advice that comes from experience… ahem.
The urge to use the restroom during exercise is caused by increased intestinal motility, likely triggered by any (or all) of the following: jostling of internal organs, relative intestinal ischemia (decreased oxygen getting to the intestines as blood is diverted to the muscles for work and to the skin to cool the body), dehydration, and adrenaline-related anxiety/stress hormones. I’ve noticed that hot weather greatly increases the likelihood of runner’s diarrhea as it contributes to additional blood diversion as well as dehydration through excessive sweating. Basically, don’t be surprised if you need to plan your summer runs around bathroom stops.
That being said, there are a few things that can decrease the urgency and frequency of this unpleasant intestinal drama:
1. Watch what you eat before your run – avoid fiber, caffeine, fake sugar, or anything that generally makes YOU have to move your bowels more frequently (milk and/or soy products are a culprit for some). Ideally, these things should be avoided up to 12-24 hours before you run.
2. Stay hydrated. Get ahead of the game by drinking a liter of water before your run and continue to hydrate during exercise (as appropriate for the climate and your effort level.)
3. Run at a slower pace if the weather is hot. I often find that dropping the pace by a minute or two per mile can magically reduce the intestinal symptoms. Interval training can help you challenge your speed limits while offering active recovery periods for your body to cool down and let your gut chill out.
4. Run in the morning when it’s cooler and you’ve had less to eat. Running after a day full of eating is looking for trouble.
5. Try to evacuate your bowels before your run – this is fairly obvious, but take the time you need to get this taken care of.
If the weather is hotter than 85 degrees, I’d consider running on a treadmill in an air conditioned space.
I found this comprehensive list of strategies to avoid the trots quite helpful. Please check it out – and good luck on your summer runs and races. Perhaps we’ll cross paths at a rest stop near you!
Dr. Oz is a powerful guy, blessed with a name that conjures up wizardry. He just unveils his latest “miracle,” which seems to happen on an almost daily basis, and people scamper off to the nearest the health food. Recently the great Oz anointed the oil extracted from the fruit of the palm tree that grows in Indonesia and Malaysia as a wonder product that can aid weight loss and reduce the risk of Alzheimer’s and heart disease. Introduced to this marvel by his a guest, a homeopath, Dr. Oz excitedly gushed about the beta carotene and “special form of vitamin E” found in “red palm oil.” A curious business. Tell me, does a Professor of Surgery at Columbia University with over 400 research publications under his belt really need advice on nutrition from a homeopath?
As is usually the case with Oz’s miracles, there is a seed of truth that then gets fertilized with lots of verbal manure until it grows into a tree that bears fruit dripping with unsubstantiated hype. For example, one study did show a reduction in the severity of cholesterol-induced atherosclerosis in rabbits fed high doses of red palm oil. This has little relevance for humans but magicians who pull rabbits out of hats may consider adding red palm oil to the diet of their little assistant. The red colour of the oil comes from beta-carotene, the same substance that contributes to the hue of carrots and many other fruits and vegetables. It is the body’s precursor for vitamin A, which makes it an important nutrient.
Unfortunately, in many areas of the developing world there is a shortage of both beta carotene and vitamin A in the diet leading to a high incidence of blindness, skin problems and even death. In such cases red palm oil would be useful, but of course there are numerous other ways to introduce beta-carotene into the diet including “golden rice” that has been genetically modified to provide the nutrient. Aside from remedying a vitamin A deficiency, there is not much evidence for increased intake of beta carotene outside of that contained in a balanced diet. There are suggestions that higher blood levels of beta carotene reduce the risk of breast cancer in high-risk women, but the beta-carotene levels may just be a marker for a better diet.
As far as the Alzheimer’s connection goes, Oz may have been referring to a study in which 74 seniors with mild dementia were compared with 158 healthy seniors. People with dementia had lower levels of beta-carotene and vitamin C in their blood. Again, this does not prove that the lower levels are responsible for the condition, they may just signal a diet that is poorer in fruits and vegetables. Tocotrienols, the “special form of vitamin E” Oz talked about, have shown some borderline effects in Alzheimer’s patients at doses way higher than found in red palm oil. There is no evidence for preventing the disease.
What about the claim that red palm oil causes loss of belly fat? That seems to come from a rat study in which a tocotrienol-rich fraction extracted from palm oil caused a reduction in fat deposits in the omentum, the tissue that surrounds organs. There was no evidence of abdominal fat reduction, and furthermore, the study involved putting the animals on an unnatural and unhealthy diet. But these are not the facts that the audience was treated to on the Dr. Oz Show.
What the eager viewers witnessed were three visually captivating but totally irrelevant demonstrations of the purported health benefits of red palm oil. First in line was a piece of apple that had turned brown because of “oxidation.” This could be prevented with a squirt of lemon juice, Oz explained. Then came the claim that red palm oil protects our brain the same way that lemon juice protects the apple. This is absurd. Vitamin C inactivates polyphenol oxidase, the enzyme that allows oxygen to react with polyphenols in the apple resulting in the browning. The human brain, however, bears no resemblance to an apple, except perhaps for the brains of those who think it does. Yes, oxidation is a process that goes on in the human body all the time and has been linked with aging but suggesting that beta-carotene because of its antioxidant effects protects the brain like lemon juice protects the apple is inane.
Just as zany was the next demo in which two pieces of plastic half-pipe representing arteries were shown with clumps of some white guck, supposedly deposits that lead to heart disease. Oz poured a gooey liquid, representing “bad fats” down one of the tubes, highlighting that it stuck to the goo. Then he proceeded to pour red palm oil down the other pipe and lo and behold, the deposits washed away. Totally meaningless and physiological nonsense. The homeopath then explained that saturated fats behave like thick molasses cruising through the cardiovascular system, but palm oil does not, despite being high in saturated fats. While saturated fats may lead to deposits, they do not do this by “thickening” the blood. Arterial deposits are the result of some very complex biochemistry and are not caused by “sludge” in the blood. Oz even exclaimed that this demo was indicative of how red palm oil reduces cholesterol in a month by 40%, better than drugs. A search of Pubmed reveals no such study.
The final demonstration involved Dr. Oz lighting a candle and a flare, without wearing safety glasses mind you. The message seemed to be that the body burns most fats slowly, but it burns red palm oil with great efficiency, preventing weight gain. Where does this come from? Possibly some confusion about medium chain triglycerides which are somewhat faster metabolized than other fats. But these are not found in palm oil. They are found in coconut oil and palm kernel oil. Oz and his homeopath expert were as confused about this as about the rest of red palm oil info they belched out.
Aside from scientists who took issue with the misleading information, animal rights groups also attacked Oz’ exhortations about the benefits of the oil claiming that it will lead to destroying larger stretches of the jungle, home to many wild creatures including the orangutan. They maintain that when the jungle is cleared every living creature is either captured or killed and adult orangutans are often shot on sight. A tragedy. Another tragedy is that Dr. Oz could be doing so much good if he just focused on real science, as he sometimes does, instead of drooling over the latest “miracle” as presented by some pseudo expert.
Joe Schwarcz, Ph.D., is the Director of McGill University’s Office for Science and Society and teaches a variety of courses in McGill’s Chemistry Department and in the Faculty of Medicine with emphasis on health issues, including aspects of “Alternative Medicine”. He is well known for his informative and entertaining public lectures on topics ranging from the chemistry of love to the science of aging. Using stage magic to make scientific points is one of his specialties.