Gwyneth Paltrow’s announcement that she has the beginning stages of osteopenia (low bone mineral density) has led to speculation that her low vitamin D levels may be a consequence of her macrobiotic diet.
Now, a lot of people are thinking twice about their own diet schemes.
We’ve written before about how liquid cleanse diets can dehydrate you and hurt your heart. However, there are plenty of diets that are less extreme but still potentially harmful to your health.
I spoke to two experts: Dr. Felicia Stoler, a registered dietitian and host of Honey, We're Killing the Kids! on TLC, and Marjorie Nolan, a New York City–based registered dietitian, certified personal trainer, and spokesperson for the American Dietetic Association. They both agree that there is a lot that dieters should look out for.
“Any kind of crash diet or fast weight-loss plan should be a red flag,” Nolan says. “You’ll miss out on nutrients, weaken your immune system, and set yourself up to get sick.”
And it’s not a myth that crash diets slow down your metabolism and you end up on a yo-yo cycle. “Even if you eat a diet that’s adequate in calories, if it cuts out an entire food group, you’re setting yourself up for problems,” she says.
Here are other things dieters should watch out for:
Following a macrobiotic diet. A macrobiotic diet can be adequate, but it’s difficult to get enough protein, calcium, and calories if you don’t plan carefully, Nolan explains.
“You may not get enough protein for your muscles to rebuild themselves. And if you don’t get enough calcium or protein, in general, your body’s not able to use vitamins and minerals properly.”
Taking vitamin supplements to make up for nutrients you don’t eat. “A lot of people think that if they take supplements, they’re OK. That’s a huge misconception,” says Nolan. If your weight-loss plan is too low in calories overall, the vitamins and minerals aren’t going to make it into your cells, and your body won’t be able to use them efficiently.
Going on a gluten-free diet. “Sometimes people get a little grumble in their tummy and so they self-diagnose as being gluten intolerant, and they wipe out an entire food group. They also wipe out essential nutrients the body needs,” says Stoler.
People who are gluten intolerant can get those nutrients by eating other whole grains that don’t contain gluten, such as quinoa, rice, or amaranth.
And, going gluten-free doesn’t mean you’ll lose weight. “A gluten-free diet can be very healthy,” says Nolan, “but it is not necessarily very low in calories or fat.”
For example, compared with regular bread, gluten-free bread is much denser because the protein that would normally come from wheat is removed. That equates to a calorie count that is 30% to 40% higher than in gluten-containing products.
Cutting out “white foods.” As with gluten-free diets, cutting out “white foods” isn’t necessarily going to guarantee you’ll lose weight. “The white food—it’s the bane of my existence!” says Stoler. “I keep telling people, ‘It’s not the rice! It’s not the white flour!’ People all over the world eat white flour. Our problem is that we eat too much!”
Pursuing vegetarian and vegan diets the wrong way. “Protein helps you feel full longer,” Nolan says. “People cut back on their protein thinking it'll help them lose weight, but instead they may be setting themselves up for a binge from feeling hungry throughout the day.”
You are also more likely to have low blood sugar on a vegetarian diet. “If a woman cuts out meat to lose weight and she cuts back on fat intake, too, all she has left is carbs and she’ll be hungrier,” says Nolan. So if you go vegetarian or vegan, be sure to carefully plan your protein intake, eating plenty of nuts, beans, and low-fat yogurt (if you eat dairy) the entire day.
Be wary of hormone-based diets. HCG diets are making a comeback, and they're based on very low-calorie diets (500 a day, typically) and regular doses of HCG, a hormone usually produced by a woman’s body during pregnancy.
Not only is the caloric amount too low to support your base metabolism, but also the Seattle Times reported on some very frightening side effects, including excessive ovulation. Please, don’t do it.
Bottom line: Watch out for diets that eliminate entire food groups, and don’t cut calories below what your body requires. (Use a RMR calculator to find out the minimum number of calories you need to eat a day.)
Even if you choose to avoid certain foods for ethical and moral reasons, you can still get the nutrients they deliver from other food sources. See a dietitian if you need help customizing a plan that keeps your body healthy.