Despite the steady drumbeat of bad news about artificial sweeteners, many people find their daily diet drink a hard habit to break. If you can’t bring yourself to give up diet soda for your own sake, maybe you can do it for your unborn child. Continue reading “Pregnant? Skip the Diet Soda”
If you are unhappy with your weight or frustrated by your inability to lose weight, you’ve probably wondered whether a slow metabolism may be to blame.
Your suspicions may have been confirmed by all the diets, programs, and products out there that claim to “fix” a slow metabolism. Let’s take a closer look at what factors have an impact—either positive or negative—on our metabolism and how big that effect might be.
This article is also available as a podcast. Click to listen.
First, let’s define some terms. In this context, metabolism refers to your resting metabolic rate (RMR). This is the amount of energy your body uses just to maintain basic biological functions like breathing, pumping blood, blinking, and maintaining your body temperature.
For a healthy adult, this is somewhere in the neighborhood of 1200 to 1600 calories per day. However, there are some things that can lower the number of calories your body burns in “maintenance” mode–or slow your metabolism
Losing weight. This strikes a lot of people as criminally unfair but the truth is that the smaller your body, the fewer calories it takes to maintain it. But the effect is greatly amplified when you lose weight quickly.
Restricting calories. Dramatically restricting calories for more than a few days can also affect your metabolism—and that’s above and beyond the effect of any weight loss that this causes.
Losing muscle. Lean muscle tissue is more metabolically active than other tissues such as bone and fat. So when you lose muscle, your metabolism slows. Yet another problem with rapid weight loss is that you lose a lot of muscle tissue in addition to losing fat.
See also: How much fat can you lose?
Getting older. We also tend to lose muscle tissue as we get older, which leads to a slower metabolism. As a result, we generally need fewer calories as we age.
Low thyroid function. One of the many things the thyroid gland does is to regulate metabolism. If your thyroid gland is not producing enough thyroid hormone, your metabolism slows. You can have your thyroid function tested if you suspect that it is a factor. If it is low, your doctor will probably suggest replacement thyroid hormone, which can help.
The best way to protect yourself against these metabolism-slowing factors is to avoid quick weight loss and extended fasting or very low calorie diets. If you are losing weight, take your time, and be sure to consume sufficient protein, which helps to prevent the loss of muscle during weight less. And although there’s nothing you can do to avoid getting older, you can slow age related loss of muscle tissue by increasing your protein intake.
Avoiding the things that can slow your metabolism down is one thing. But is there anything you can do to speed it up?
Obviously, you can burn more calories by exercising more. But there are only so many hours in the day–how many of them can you spend at the gym? If you could somehow somehow arrange to burn more calories just maintaining your basic biological functions, that could really help with weight control. And there are a few things that have been shown to increase resting metabolism (although there is a catch).
Gain muscle. Just as losing weight decreases the number of calories you burn, gaining weight increases the number of calories you burn–especially if you gain lean muscle. Strength training to increase your muscle mass can help you burn more calories.
Eat more protein. Protein takes a little more effort for your body to digest than fat or carbohydrate, so increasing the amount of protein in your diet can help you burn more calories. It can also help you gain more muscle.
Chill. Your body burns calories in order to keep your body warm. The cooler your environment, the more calories it takes. Turning down the heat, taking cold showers, and drinking ice water can all increase your calorie burn.
Your body burns calories in order to keep your body warm. The cooler your environment, the more calories it takes.
And finally, everyone’s favorite way to increase your metabolism:
Eat metabolism-boosting foods. There are also some foods and herbs, including hot peppers, vinegar (any kind), garcinia, and green tea, which have been demonstrated to increase the rate at which your body burns calories.
If these metabolism boosting techniques could increase your resting metabolism by 10%, this could add up to an extra 120 to 160 calories burned every day. Over the course of one month, you could theoretically lose a pound of fat.
Unfortunately, turning down the heat and eating more protein, hot peppers and green tea isn’t going to boost your metabolism anywhere near 10%. At best, you might burn an extra 10-20 calories a day, or enough to burn an extra pound or two per year.
Trying to lose weight by boosting your resting metabolism is like trying to row a boat with a butter knife. You’re going to be rowing for an awfully long time without moving very far.
There are more effective ways to pursue weight loss, such as those I outlined in my episode on how to lose weight without dieting and those I use in my weight management coaching program. But it’s definitely worth your while to avoid things that may slow your metabolism–such as severe dieting and fast weight loss.
Laurie writes:
“In the last year I’ve changed my diet and added back good fats like avocado, nuts and seeds (which I used to avoid due to fear of fat). I also started making kefir and yogurt. I feel SO much better. However, the added calories have slowly added pounds. So my question is….How do we fit in all the healthy foods we need to be eating and still limit calories?”
You’re not the first to have this dilemma, Laurie! Nuts, seeds, and avocados are all healthy foods but it is possible to get too much of a good thing. Continue Reading
Kate writes:
“I am a [lacto]vegetarian, and I make sure to get 3 servings of dairy every day. However, I still technically fall short of the recommended amount of calcium. I have a conspiracy theory that the dairy industry has undue influence on the [USDA], and that the calcium requirements are higher than they need to be. I am interested in hearing your thoughts on how accurate the RDA for calcium is, and any tips for getting the needed level on a vegan or vegetarian diet (without resorting to supplements or fortified foods).”
I can see how Kate gets there. The USDA is the government agency responsible for generating our nutrition guidelines. But it is also the government agency responsible for promoting the welfare of our nation’s dairy farmers. Is it possible that the desire to promote milk consumption has prompted the USDA to inflate the recommended amount of calcium? Sure. Weirder things have happened.
But having read through (some of) the scientific documentation for our dietary recommendations, I can assure you that they are not written by dairy farmers. These are nutrition geeks to the nth degree, hashing out issues such as urinary losses, intestinal absorption rates, insensible losses, nutrient interactions, risk profiles, and everything else you can think of.
That said, nutrient needs for various populations are determined in the context of the prevailing diet and lifestyle. It is possible that calcium requirements may be higher for those consuming a typical Western diet than they are in developing nations.
For insight, we can step outside the USDA and look at a more global picture. The World Health Organization compiles and compares the work of nutrition geeks from all over the world. Here’s an interesting table from a their 2004 report on Vitamin and Mineral Requirements in Human Nutrition (sure to be this summer’s hot beach read.)
You can see that the recommendations are somewhat higher in the US than other largely Caucasian Western countries. However, the WHO reviewers point out that the lower numbers from the United Kingdom and Australia do not take into account insensible losses and that the British and European values make no allowance for aging or menopause. (Maybe our geeks are more thorough than their geeks?)
The WHO report goes on to note that other factors, such as race, geography, lifestyle and diet composition may also affect calcium requirements. Specifically, calcium requirements may be lower in diets that are lower in animal protein and sodium.
But why do we care so much about calcium in the first place? Primarily because of bone health. And surprisingly enough, higher protein diets actually appear to promote healthier bones. Go figure.
The bottom line? Nutrition is not an exact science. Getting 1000 mg of calcium per day doesn’t guarantee that you’ll never have osteoporosis, and getting 800 mg per day doesn’t guarantee that you will. In fact, I think our focus on calcium tends to obscure all the other dietary and lifestyle factors that add up to healthy bones.
Liv writes, “I’m expecting a baby and am supposed to avoid unpasteurized milk. I assume that pasteurization would kill the live cultures in yogurt. Is there another way to get the benefits of beneficial bacteria while I’m pregnant?” Continue reading “Are fermented foods safe during pregnancy?”
If you’ve been enjoying the Flax Muffin in a Mug recipe I recently shared in the Inner Circle newsletter, then you’re going to LOVE this make-ahead version I’ve developed, which makes it even easier to bake up a hot and wholesome breakfast treat on the go. Continue Reading
Cathy writes:
“Regarding the recent Nutrition Diva episode about artificial sweeteners, how exactly do you define “artificial” when it comes to sweeteners?”
Cathy is absolutely right that the terminology used to talk about sweeteners is vague and I should be better about defining my terms!
Sweeteners can be divided into two broad categories: caloric and non-caloric. Even there, it gets fuzzy because virtually all “non-caloric” sweeteners are not truly zero-calorie, just so low in calories that we consider them non-caloric.
I think it’s smart to limit your consumption of both caloric and non-caloric sweeteners to around 5% of calories (or the equivalent amount of noncaloric options).
See also: What’s a safe intake of noncaloric sweetener?
Although we often use words like natural, processed, refined, synthetic, and artificial to describe various caloric and non-caloric sweeteners, these are not precisely defined terms or categories. Continue reading “Is stevia an artificial sweetener?”
Karina writes: “I am a fan of low-fat dairy. I prefer skimmed milk and fat-free yoghurt. But lately, people have been telling me that low-fat dairy is “bad for you ” and full fat is better. When I ask why, they say it’s something to do with how the fat is removed. Another person says most of the nutrients are in the fat. What is your take on it?” Continue reading “How Bad for You is Lowfat Milk?”