When Your Healthy Diet Isn't So Healthy

Trying to eat healthier? Great. Just avoid these 9 common diet mistakes.

Medically Reviewed by Kathleen M. Zelman, RD, LD, MPH on July 17, 2011
7 min read

One of the happiest days of my life was when I found out that chocolate (yes, chocolate!) was actually good for me. The rich, creamy candy I'd been surreptitiously snacking on since I was a kid was packed with heart-healthy antioxidants.

I gleefully loaded up my shopping cart with bars and bags of chocolate -- dark, of course -- and gorged myself silly.

Then I came to another realization. Dark chocolate, though undoubtedly healthy in small quantities, happens to also be loaded with sugar and fat. I owed my thighs a sincere apology.

The problem is, there is no quick fix when it comes to healthy eating.

"A healthy diet relies on a lifelong commitment to eating the right foods and eating the right way," says Sari Greaves, RD, nutrition director at Step Ahead Weight Loss Center in Bedminster, N.J., and an American Dietetic Association (ADA) spokeswoman.

Even if you already knew that, you may still go astray when you try to eat healthier.

Here are a few of the most glaring diet mistakes people make, and how to fix them before they derail your healthy eating plan.

One diet promises that you can lose 10 pounds in a week by eating as much as you want -- as long as what you're eating is cabbage soup. Or grapefruit. Or cookies.

Bad idea.

If you go on an extreme, short-term diet, "you're setting yourself up to be very hungry and then bingeing," says Marjorie Nolan, MS, RD, CDN, CPT, a registered dietitian in New York and national ADA spokeswoman.

By cutting out entire food groups, you're also prone to nutritional shortfalls and boredom. Eventually, you're going to crave the foods you're missing.

"Even when the diet works...it doesn't teach you how to maintain your weight loss. It's just a gimmick to restrict calories," Nolan says.

Some of the one-food diets can also have unpleasant side effects. Grapefruit acts as a diuretic, which can lead to dehydration, Nolan says. It can also make you gassy and can interact with some drugs, such as those that treat high blood pressure and abnormal heart rhythms.

Fix It: "The bottom line is, if a product or diet sounds too good to be true, it probably is," Greaves says. She advises steering clear of any diet that promises fast results.

"Weight loss should be a gradual process in which you lose no more than half a pound to 1 pound a week by eating a well-rounded diet," Greaves says.

More than 7 million people in the U.S follow a vegetarian diet. Most of them do it with the best of intentions. Either they love animals too much to eat them, or they're opting for what they see as a healthier lifestyle. A healthy vegetarian diet has been linked to lower rates of obesity, diabetes, and heart disease.

What many people don't realize is that vegetarian doesn't necessarily mean low-fat or low-calorie.

"If you're eating carbohydrate- or starch-rich foods, calorically, you might be eating more," Nolan says.

In other words, if cheese, pasta, and smoothies are the foundations of your vegetarian diet, you can still gain weight and be unhealthy.

Fix it: Make vegetables the centerpiece of each meal. Add whole grains, fruit, and other healthy non-meat foods. Make sure you get enough protein from vegetable sources like beans, nuts, and tofu and essential amino acids from foods like brown rice.

A steady stream of research touts the benefits of one food or another. Chocolate, red wine, olive oil, avocados, and nuts have all had their day in the dietary sun.

True, these foods have health benefits. But that doesn't mean more is better.

For instance, chocolate, olive oil, avocados, and nuts are all high in calories. "One of my clients said...he'd heard avocados are good because he had heart disease. He was eating three avocados a day," Nolan recalls. "While they're nutrient-rich and good for you, he was eating at least 500 to 600 calories in avocados each day."

One tablespoon of olive oil has 120 calories. Red wine is alcohol, which in large quantities can raise your risk for heart problems and cancer.

Fix It: It's OK to add a healthy ingredient into your diet. But do it in moderation and as part of an overall healthy eating plan. That means a little olive oil, not a couple of glugs. Or a handful of nuts, not the whole bag. You get the idea.

What about so-called superfoods, like the açai berry -- an antioxidant-rich fruit from Central and South America -- which supposedly have amazing health benefits? Take the hype with a grain of salt, Greaves says.

"There is no such thing as a superfood," she says. "The benefit of the food is only going to be as good as your entire diet. Different foods work synergistically for your entire health." The big picture is what counts.

On the flip side of the so-called superfoods are foods that get demonized. If you purge your diet of them, you could pay a price, nutritionally.

Carbohydrates are a prime example. You do want to cut down on white bread and white rice, because these and other refined grains are low in nutrients. The U.S. government's guidelines recommend that at least half of your grains are whole grains.

Fix it: Don't cut carbohydrates entirely from your diet. "Carbs are the primary foods for energy," Nolan says. Whole-grain bread, oatmeal, and brown rice are high in fiber and rich in B vitamins like folic acid, which are nutritional essentials.

There was a time when "low-fat" and "fat-free" were dieters' mantras. Food manufacturers catered to this trend by introducing trimmed-down versions of their products, such as fat-free cookies and low-fat salad dressings -- and many people promptly went overboard.

But fat is no longer the dietary bad guy. Doctors and dietitians stress that fats are good for us. We need them.

"Fat is a component of every cell in our body. In order to be as effective as possible metabolically for our cells to do their jobs, we need to have fat in our diet," Nolan says.

Fat is especially important at every meal when you're dieting, she says. "Fat helps you stay full. It satiates you. If you cut all of the fat out of your diet or have very little fat, your blood sugar doesn't stay stable for as long a period of time and you notice that you're hungry sooner," Nolan says.

Fix it: Choose healthier fats -- unsaturated fats from plant sources -- and not too much.

Nuts, seeds, and vegetable oils like canola or olive oil are the healthiest kinds. Fatty fish are a great source of heart- and brain-healthy omega-3 fatty acids. The FDA and EPA recommend that women of childbearing age not eat shark, swordfish, king mackerel, or tilefish because those fish contain high levels of mercury; to eat up to 12 ounces per week (about two average servings) of a variety of lower-mercury fish and shellfish, and to limit albacore ("white") tuna to 6 ounces per week.

How many of us have punished ourselves for putting on a few pounds by going into a state of denial? We deny ourselves sweets, fats, and just about every food that makes us happy.

Cutting out your favorite foods only sets you up for failure. When you feel hungry all the time, you're more likely to binge. "I think it's really unrealistic for most people to eat that way for the long-term," Nolan says.

Fix it: Don't give up your favorite foods. Just eat them in moderation.

"It's all about small splurges without being overindulgent when it comes to very calorie-dense foods," Greaves says. She suggests combining sweets with healthy foods, like drizzling melted chocolate over strawberries, or adding a few chocolate chips into your granola.

Another recent dieting trend is substituting six small snacks for the old three meals a day.

Grazing does have advantages. It keeps your blood sugar level stable throughout the day, so you don’t get as hungry.

The trouble with grazing is that you're eating throughout the day, which can spell calorie trouble.

"If you're used to eating fuller meals and then you start grazing, I think it's very easy to graze on larger quantities than what you should be eating," Nolan says. "So you might end up eating more calories."

Fix it: Pace yourself. Eat mini-meals about every two to three hours, limiting each to 200-300 calories.

If you're trying to lose weight, do it in a way that's going to last. Or the pounds are going to come back.

"I think when you're going on a diet, the most important thing is to find a way of eating that suits your lifestyle," Greaves says. "Ask yourself when it comes to any new diet, 'Can I eat this way for the rest of my life?' If the answer is 'no,' that's probably not the diet for you."

Fix it: If you want to lose weight, instead of going on a radical diet, make tiny changes in your life. Add more fresh fruits and vegetables to your meals. Eat a healthy breakfast every morning -- a habit that research shows can help control your weight.

Move more, too. Aim for 30-60 minutes of exercise into every day. "Tiny little changes are the ones that will have the biggest results for your long-term health," Greaves says.