Nutrition: Myths of Weight Management
Guest: Tonya Turner – Dietetic Services, MUSC
Host: Dr. Linda Austin – Psychiatry, MUSC
Dr. Linda Austin: I’m Dr. Linda Austin. I’m interviewing Tonya Turner, who is a registered dietician at the MUSC Weight Management Center. Tonya, let’s talk about some of the myths that are out there about weight loss that we hear so much. I’ll mention some of the ones I’ve heard, and maybe you have some of your own to add. One very common one is that you’re supposed to drink eight glasses of water; that helps you to lose weight. What’s the truth about that?
Tonya Turner: There’s actually no scientific research looking at how much fluid you need to consume for weight loss. So, the 64 ounces, really, the source for this information is unknown. You’re definitely encouraged to drink water to help with satiety, but the actual amount isn’t necessarily 64 ounces, or eight glasses a day.
Dr. Linda Austin: So, maybe, just drinking as much as you feel like you need to is fine?
Tonya Turner: Exactly. It’s more to help you with satiety between meals than anything else.
Dr. Linda Austin: So often you hear people say that they have a very slow metabolism, or that someone has a very fast metabolism. How can that really be? I mean, biology is biology. Biochemistry is biochemistry. Is there really a difference from one person to next in regards to metabolism?
Tonya Turner: Not really. I mean, you’re going to consider, obviously, someone’s metabolism given their age, their gender, height and weight, and activity level. But, for somebody to have a slow metabolism; unless there’s actually a thyroid deficiency, there really is no such thing as a slower metabolism.
Dr. Linda Austin: How about, you hear women say that when they go through menopause it seems as if their metabolism changes? Does it really, or is that their activity level changes, or, maybe, fat and muscle ratios change?
Tonya Turner: It’s actually more their fat and muscle ratio. As we age, we tend to decrease our lean body mass, and increase our fat mass; just, generally, as we age. So, you do have a slight slowing of your metabolism, but probably not as dramatic as most females after menopause would think.
Dr. Linda Austin: So, then, if a woman going through menopause, or, for that matter, at any age, really works to maintain her muscle tone, and muscle mass, the number of calories she could consume without gaining weight would not change?
Tonya Turner: It would definitely help. Exactly.
Dr. Linda Austin: Okay. Now, another one out there is that if you diet, it can permanently alter your metabolism so that you will rebound more quickly once you stop dieting. Is that true?
Tonya Turner: Not really. Typically, when you start a diet, you’re going to have a slight decrease in your metabolism because you’re experiencing a large calorie deficit for what your body actually needs. However, as you get closer to your goal weight, that deficit is going to decrease. If you were to regain your weight, your metabolism is basically going to return to where it was prior to dieting. So, it’s not going to change dramatically if you continue to diet on and off.
Dr. Linda Austin: So, let’s imagine that you lost, say, ten percent of your body weight, would you then need to decrease your caloric intake by, roughly, ten percent in order to keep that weight off? Is the problem that people go back to their old eating habits?
Tonya Turner: Yes. You would have to decrease your calorie intake slightly to maintain that weight loss. Most people regain the weight not because of a slower metabolism, but because, just like you said, they go back to their old habits; increasing their portions, taking in more calories, potentially even decreasing the amount of exercise that they were doing when you were losing weight.
Dr. Linda Austin: Are there any special recommendations you give to people once they’ve lost weight in order to keep the weight off?
Tonya Turner: Definitely. Continue monitoring what they’re doing. Weigh yourself. Know exactly where you’re at. Continue to recheck your portion sizes so they don’t start to become larger over time. Constantly look at whether or not you’re eating more and exercising less. Always be aware of what you’re doing.
Dr. Linda Austin: What are some of the myths, and misconceptions, that you hear? I’m sure you’ve heard them all.
Tonya Turner: The biggest one, probably, is when you’re dieting and decreasing your carbohydrate intake that you’ll automatically gain weight if you resume eating carbohydrates again. That’s not necessarily true. Calories in to calories out is the basic mathematic equation. So, if you take in excess calories; whether as carbohydrates, protein, or fat, you’re going to see a weight gain. And, typically, with carbohydrates, all you’re really seeing is a fluid shift, as they tend to hold more water in our muscles.
Dr. Linda Austin: Now, will carbohydrates do that indefinitely? Italians, for example, who eat a lot of pasta, or, for that matter, Asians, who eat a lot of rice, won’t continue to gain weight? They’ll hold onto, let’s say, a few pounds of water to support carbohydrate metabolism, but won’t continue to gain weight?
Tonya Turner: Correct. If someone were to decrease their carbohydrate intake while dieting; like with the Atkins diet, then bring carbs back in, it’s more of just fluid shifting up. You probably lost a lot of fluid in the first couple weeks of dieting, and your body’s just basically going back to normal. You won’t continue to gain weight from fluid.
Dr. Linda Austin: Does the Atkins diet, or a high-protein/low-carbohydrate diet, have any advantage from a strictly caloric point of view?
Tonya Turner: Something as low-carbohydrate as the Atkins diet doesn’t really have any nutritional value per se. The protein in the diet does help, especially females, to maintain lean body mass while losing white. And it definitely helps with satiety. But a very low-carbohydrate/high-protein diet isn’t necessarily recommended when considering something more balanced.
Dr. Linda Austin: As with every dietician that I’ve interviewed for these podcasts, the key is, really, a balanced diet and portion control.
Tonya Turner: Exactly.
Dr. Linda Austin: You’re going to have to do it sooner or later, so you might as well get used to it.
Tonya Turner: Exactly.
Dr. Linda Austin: I guess the reason, though, that the high-protein has taken off is that you do have that very rapid initial water loss, which is kind of exciting when you step on the scale and you’ve lost that first five pounds in two days; due to water restriction. But then you gain it right back as soon as you eat that first bowl of pasta.
Tonya Turner: Exactly. Although, it does help with satiety. You do tend to feel more satisfied with protein. But you don’t necessarily need a high-protein diet.
A moderate amount of protein is fine.
Dr. Linda Austin: One hears, for example, of diets that really focus on one food; like ice cream, or whatever. Do they have any particular benefit?
Tonya Turner: No. Going back to having a balance, really, there is no such thing as a good or a bad food. You, really, can incorporate any food into a diet as long you practice portion control. A lot of diets focused on kind of red and green light foods may offer some benefit for the short term. But, for the long term, you’re not going to be able to maintain a restrictive diet like that, which is why they’re not recommended by most dieticians.
Dr. Linda Austin: What do you recommend to folks about exercise when they’re dieting?
Tonya Turner: Exercise, in general, is recommended not only when you’re dieting, but just as a matter of course. Most of our exercise physiologists at the Weight Management Center recommend at least 30 minutes of cardiovascular activity most days of the week; about five to six days per week.
Dr. Linda Austin: Thanks so much for talking with us today.
Tonya Turner: You’re welcome. Thank you.
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