This year, athletes and celebrities praised the gluten free diet as the panacea to nearly everything—from winning top tennis tournaments to red carpet ready for the Oscars. Plenty of studies showed our erratic sleep patterns make our waists bigger. Almost every health magazine welcomed back fats to our plates while vitamin D seems to aid on keeping everyone’s weight in check.

From all these diet related trends, some came to stay while others should be taken with a grain of salt. So, before you embrace—or if you already did—any of these weight control plans you need to know if they are really worth it.

Here is my look at some popular dietary trends, how they work, and whether they are truly a passing trend or something you should consider.


1. Gluten free diet: Trend

Gluten free diets are for people diagnosed with celiac disease or suffer from gluten sensitivity. If you do have either problem, a gluten free diet helps alleviates inflammation or damage to the intestinal tract, says Sharon Ritcher, R.D. from New York. However, gluten-free has been viewed as a sure-fire weight loss strategy.

If you switched to a gluten free diet thinking that this will make you lose weight, be cautious. “A gluten-free diet, as typically followed, may be high in fat and low in fiber and many vitamins and minerals, including iron, calcium, folate, and niacin,” says Tricia Thompson, MS, RD, a nutrition consultant for celiac disease. “Many prepared gluten-free foods are made from refined flours—white rice flour, milled corn—and starch like corn starch and tapioca starch, and as a result contain very little in the way of nutritional value. Potato chips and French fries are gluten-free but not necessarily the healthiest options.”

Regardless, the food industry claims many benefits of eating gluten-free, ranging from stopping hip pain to a better sleep. Some people may experience these benefits because they could have an underlying intolerance to gluten that hasn’t been diagnosed. Oftentimes, it’s the other ingredients in food that contain gluten that is to blame, such as dairy, corn, or eggs that cause the problem, explains Carol Fenster, author of 125 Gluten-Free Vegetarian Recipes (2011).

People could also lose weight on a gluten-free diet because gluten is usually present in high-calorie items, such as baked goods, pasta, and desserts. “People would lose weight by eliminating these foods whether gluten was present in the foods or not,” says Fenster.

The Takeaway:  Be a gluten free advocate if you have been diagnosed with celiac disease or gluten sensitivity. You don’t need to be gluten-free to stay away from chips, white flour, and refined carbohydrates.


2. Fat free: Remain—but think in terms of healthy fats

“People see fat and they think fat makes you fat,” says Ritcher. The truth is that overeating any macronutrient, whether carbohydrate, protein, or fat, will tilt the scale. American swapped the oil for the sugar—particularly added sugar, not the one that comes naturally in fruits and veggies—based on the general health consensus that stated fats were to blame for the increase in heart disease and weight gain.

The results: the fat free and the sugar industries exploded. Worse are the numbers on the overweight-obesity statistics as well as the rise of heart disease and other conditions that have an inflammatory component, such as diabetes and metabolic syndrome, which are related to high intake of sugar.

All organs need fat to function at its best, but not all fats are created equal. Some fats—such as monosaturated fats found in olive oil and avocado, and omega 3- fatty acids found in salmon and some seeds—have anti-inflammatory properties, and help reduce belly fat reduction and even boost moods.

The Takeaway: Fats can help you slim your waist, but know which ones are the best to include in your diet.  This is what Barry Sears, Ph.D., author of The Zone Diet, advises as the correct health ranking of fats from best to worse: Long-chain omega-3 fats (EPA and DHA like found in salmon, mackerel, sardines, and albacore); short chain-omega-3 (flaxseed oil); monounsaturated fats (olive oil); long, medium, and short-chain saturated fats, such as palm oil, coconut oil, cocoa butter, and butterfat; omega-6 fats found in oils like soybean, canola, safflower, and corn; and arachidonic acid (usually found in dressings, chips, fast food, and meats.


3. Paleo Diet:  Be cautious

What’s the Paleo or “Caveman” Diet? “Basically, eating lean proteins and any fruit/vegetable that was found pre-agricultural revolution. Very restrictive in other foods,” says Bob Seebohar, MS, RD, CSSD, CSCS, author of Nutrition Periodization for Athletes.

It seems that fitness programs, such as Cross-Fit, Tabata, and other high intensity interval training workouts are good at promoting a protein rich diet. However, while the role of this nutrient has been well documented to maintain a healthy body mass and metabolism, and decrease body fat, experts advise on the health hazards of overconsumption—especially when other nutrients rich in fiber and vitamins and minerals are put aside.

“Any diet that eliminates a food group, eliminates essential nutrients,” says Shari Portnoy, M.P.H., R.D., Indeed, the Paleo avoids grains and dairy and even though it promotes high fruit and vegetable intake, the overall carbohydrates consumption may be insufficient.

To Portnoy, the body needs carbohydrate meals to fuel and refuel properly, adding, “The brain runs on glucose only, a fuel received from carbohydrates. Using protein for fuel is inefficient because then what do you have left to build and repair muscle tissue?”

Eating more fruits and vegetables is always good, but keep in mind you need at least 10 servings to meet carbohydrate needs for short, intense exercise, says Seebohar. However, statistics show that Americans have a tough time meeting five servings a day so it is unrealistic to expect followers of Paleo to double that amount.

The Takeaway: have more lean protein, healthy fats, fruits and veggies—but do not eliminate whole grains, such as quinoa, brown rice, bulgur, amaranth, etc. And don’t avoid skim dairy food sources either. If anything, fiber, calcium and vitamin D have been shown to decrease abdominal fat.


4. Foods with added benefits: Remain—but be cautious

Are you confused at the grocery store when looking at so many products with added fiber, omega-3, probiotics, etc? You’re not alone. No wonder more than 50 percent of Americans think it is easier to fill out their taxes than understand food labels.

Take flaxseed content claims, for example. Flaxseeds have been shown as protector against cancer and an anti-inflammatory. They are rich in folate, other B vitamins, iron, protein, and fiber. But does the tiny flaxseed content in a bar filled with so many other artificial ingredients really make a specific food healthy?

“My own view is that because there is currently no one accepted or regulated definition of ‘functional foods,’ the term is best interpreted as a marketing tool designed to sell products. And we know that promoting foods showing particular health benefits can have a powerful effect on sales,” says Amanda Berhaupt-Glickstein, MS, RD, co-author of the study “Functional Foods. Perceptions, Attitudes, and Practices of Registered Dietitians,” published in Topics in Clinical Nutrition.

The Takeaway: An easy way to avoid falling for food-marketing gimmicks is to simply select the whole food over processed version even when something healthy-sounding has been added. So if your goal is to have more calcium in your diet, make sure to consume skim milk, yogurt or leafy greens instead of sugary drinks with added calcium. If you want to decrease your risk of heart disease, enjoy more salmon, flaxseeds, oatmeal and potassium-rich fruits instead of a ready-to-go health bar with added fiber.


5. Sunshine vitamin deficit: Remain—but be cautious

“Up to 75 percent of people have low vitamin D levels,” says Michael Smith, M.D., WebMD’s chief medical editor. The primary role of vitamin D is to keep bones strong and prevent osteoporosis. However, there is some controversy about linking vitamin D intake to the prevention of other diseases, such as cancer and diabetes. “We just don’t know enough to say vitamin D definitely does or does not prevent these diseases,” says Smith.

More studies are piling up that connect weight loss with vitamin D. However, the best results come when this vitamin is paired with calcium-rich food.  For instance, a study published in The American Journal of Clinical Nutrition shows that both higher dairy calcium intake and increased serum vitamin D are related to greater diet-induced weight loss.

The Takeaway: Vitamin D whole foods like fatty fish, milk, yogurts, eggs and cereal are always your best bet. “You can take supplements—but it is possible to take too much vitamin D. It is a fat-soluble vitamin and can build up in the body. 4,000 mg is the upper limit, and with recommendations at 600 to 800 daily, you have a lot of room to play with. Still, you can suffer toxicity from too much vitamin,” explains Smith.

It’s always recommended you consult your doctor to measure your vitamin D levels, particularly, if you live in areas where the sunshine is scared. (Sunshine is another great source of vitamin D, but you can risk too much sun exposure.) This will be the best way to gauge if you run low on this vitamin and what are the best ways is to get adequate amounts.


6. Sleep to lose weight: Remain

Lack of sleep will make you increase both your pant’s size and risk of heart disease and diabetes. Numerous studies show that inadequate slumber disrupts essential hormones involved on appetite and overall metabolism. For instance, a study from Mayo Clinic in Rochester, Minnesota, showed people who sleep less than 7 hours, eat on average 549 calories more a day than those who sleep 8 hours.

“Lack of sleep affects hormone levels that regulate appetite. The hormone ghrelin—which stimulates appetite—goes up. And levels of leptin, which normally sends the ‘I’m full’ message to your brain, fall so you eat more,” says Smith. “Sleep loss also stimulates cravings for high fat and high carb foods for energy.”

The Takeaway: Take your sleep hygiene seriously. No matter if you are active and follow a clean diet, sacrificing a good night’s sleep will harm your overall health.