The internet is filled with articles on superfoods for dieting and weight loss. But, where is the research to back it up?
Just knowing a superfood is healthy doesn’t automatically mean you’re going to lose weight by eating it, especially when it’s mixed in sporadically with an otherwise regular, or higher fat and calorie diet.
Instead of going on a strict diet, make a lifestyle change with a menu that includes superfoods, as well as regular exercise, to boost your weight loss potential.
Research suggests that while all superfoods are great for your health, sometimes pairing them with other superfoods[1] can actually boost weight loss.
Dr. Steven Pratt, MD, author of The SuperfoodsRx Diet, has done extensive research on superfoods and how they affect your health and weight loss.
All of the studies cited in this article are highlighted in The SuperfoodsRx Diet, which is worth a read for anyone who is interested in weight loss with superfoods or even just a healthy diet and lifestyle.
Why do many cleanses and fad diets fail?
When your body doesn’t get proper nutrition, it’s almost impossible to lose weight. The reason is because your body needs a sustained and gradual release of blood glucose that’s found in wholesome, high-fiber, and nutrient-rich superfoods.
On the other hand, foods that are high in sugar and bad carbs can cause surges of insulin, which can cause mood swings and difficulty concentrating. Higher insulin can also result in weight gain.
A chemical in the brain called orexin is vital to mental alertness. High glucose levels can suppress orexin levels in the brain, which can cause difficulty concentrating and sleepiness.[2]
What is the SuperfoodsRx Diet?
The SuperfoodsRx diet not only promotes a healthy lifestyle change, it also allows you to ease into the diet in phases. First is a “Prep & Practice” week, followed by “The SlimDown” as you achieve your weight loss goals.
Then you move onto “The FlexPlan” after you’ve met your initial weight loss goal, but still want to lose a few more pounds. Finally, you reach “The LifePlan”, which is exactly what it sounds like—a superfoods diet for life.
Even though there are phases to the diet, the SuperfoodsRx diet is a lifestyle change that will benefit you and your family for as long as you stay on it.
Research Behind Superfoods for Weight Loss
Green Tea
What’s not to love about green tea? It tastes good, has practically zero calories, is inexpensive, and is easy to incorporate into your superfoods diet.
The active ingredient in green tea is called polyphenol, which is a powerful antioxidant that helps fight free radicals and oxidative damage.
Polyphenols are antiviral, antibacterial, and play an important role in preventing cell mutation.[3] Green tea also helps fight osteoporosis, cancer, UV damage, and cardiovascular disease.
Polyphenols are strong anti-inflammatories, which are strongly connected with obesity. The theanine in green tea can also reduce stress[4], which can lead to weight gain as well.
Researchers initially thought caffeine was the main component of weight loss associated with green tea.
However, studies now suggest epigallocatechin gallate (EGCG) has “thermogenic” properties[5] that go beyond caffeine.
This means the tea can increase metabolism by promoting calorie burning. Another study done in 2001[6] showed people who drank five 10-oz cups of Chinese oolong tea a day for 3 days had an increased metabolism of 3 percent more than those who drank water.
This means you can also incorporate black and oolong tea into your superfoods diet. Another study showed that one to two cups of tea (green, oolong, or black) have the same antioxidant effect as 5 servings of fruits and veggies or 400 mg of vitamin C.[7]
Salmon and Omega-3s
Omega-3s have been getting a lot of love lately. Fatty fish, such as wild salmon, is full of omega-3s, which are polyunsaturated fatty acids. In particular, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) work to make platelets less “sticky” and improve circulatory health.
They also promote cognitive function and reduce inflammation. Chronic inflammation can result in health conditions such as rheumatoid arthritis, asthma, and cardiovascular disease.
Chronic inflammation also causes leptin resistance, which can affect your body’s metabolism and hunger signals. Leptin plays a major role in weight loss.
One study was done on mice that were divided into three groups. One got soybean oil, one lard, and one fish oil. The group of mice that ate fish oil had lower leptin levels and visceral fat, which is harder to reduce and can also lead to cardiovascular disease.[8] Another study found that omega-3 altered the brain’s regulation of metabolism, therefore reducing the development of obesity.[9]
Another consideration is your body’s omega-6 to omega-3 ratio. An imbalance can actually increase hunger. Most people consume more omega-6 than omega-3, so eating natural sources or taking fish oil supplements are important to your superfood diet success.
Studies also indicate the type of fat you eat is important as well. A study on mice compared a diet high in saturated fat, and a diet that followed the saturated fat diet with omega-3s, showed a complete reversal of the weight gain, which wasn’t due to calorie restriction.[10]
Oranges and Kiwis
Not only are oranges a great snack and substitute for sweets, they are loaded with vitamin C. So are kiwis. Vitamin C fights cancer, stroke, and improves cardiovascular health. A study on the relationship between fat distribution and vitamin C showed that the more vitamin C intake for both men and women, the lower the waist-to-hip ratio was.
[11] Another study showed that people with adequate intake of vitamin C oxidize 30 percent more fat during moderate exercise than people who have low vitamin C levels.[12] Yet another study showed patients had significantly more weight loss by improving their vitamin C levels.[13]
Walnuts
Walnuts are a healthy fat (sort of like salmon), that are loaded with vitamins, minerals, protein, plant sterols, polyphenols, healthy fats, and fiber. They have less than 7 percent saturated fat and are a great plant source of omega-3s.
Regularly consuming nuts can reduce the risk of coronary heart disease, certain cancers, diabetes, and other chronic conditions. In fact, consuming nuts is associated with reduction of all causes of mortality.[14]
Some people are hesitant to add nuts to their weight loss diet because they are “high in fat,” but studies actually show that people who regularly eat nuts have a lower body weight than those who don’t.[15] It’s possible that nuts suppress appetite and fat absorption.[16] A large study done on 8,865 adults watched participants’ eating patterns, taking into account age, sex, smoking, physical activity, and other obesity risk factors.
The study concluded that participants who ate nuts at least twice a week had a much lower risk of weight gain than those who rarely or never consumed nuts.[17]
Nuts can also improve insulin sensitivity, which may be why nuts can suppress appetite. One thing to keep in mind, however, is that portion size is everything when consuming nuts.
Nuts are high in calories and fat (even if it’s the good kind), so more than a handful or two a day can undo some of your weight loss efforts. SuperfoodsRx recommends thinking of nuts like condiments—use small pieces to sprinkle on yogurt or oatmeal.
Yogurt
There are lots of yogurt options available at the supermarket: greek yogurt, flavored yogurt, probiotic yogurt, unflavored yogurt, etc.
There are a plethora of health conditions that yogurt can help, such as inflammatory bowel disease, irritable bowel syndrome, cholesterol, allergies, certain cancers, lactose intolerance, diarrhea, yeast infections, and urinary tract infections.
The benefit is the “live active cultures” and high level of calcium. Live active cultures are created in yogurt when milk lactose (or sugar) is turned into lactic acid through friendly bacteria. Unlike whole milk, yogurt has low saturated fat levels.
Some studies are now suggesting that people who have high levels of calcium in their diet are less likely to gain weight by 60 to 80 percent[18].
A separate 2-year study focusing on young women watched their nutrition and body composition. The study concluded that over the 2-year period, women who had a high calcium intake gained less body weight and body fat than women with a lower calcium intake.[19] One study was done on yogurt in particular.
It concluded that over a 12-week period, 34 obese adults that were on a reduced-calorie diet and consumed 3 servings of yogurt per day lost 22 percent more weight, 61 percent more body fat, 81 percent more fat around the middle (visceral fat) when compared to low-dairy diets.[20]
So, why do researchers think calcium has such a big effect on weight? There are a few possible reasons. Calcium directly affects the body’s energy metabolism. So, when you have low calcium levels, your body produces parathyroid hormones (PTH).
This means the body reads low calcium as a “starvation” mode and subsequently stores excess fat and energy for future use. Not only is calcium important in weight loss, healthy GI bacteria, or flora, impacts how your body metabolizes calories. Another bonus to eating a calcium-rich diet is the added benefit of bone and muscle protection, since bone or muscle loss can be a risk of weight loss programs.
Soy
Soy has gotten a lot of good, and some negative, press. However, there is a lot of good research out there on soy, and even on soy’s connection to weight loss.
These benefits come from whole soy foods (such as edamame, tofu, soy nuts, soy milk, tempeh, and miso), not from soy supplements. Soy is beneficial for cardiovascular health by lowering both blood pressure and cholesterol.
Other health benefits of soy include lower risk of cancer, bone fracture, osteoporosis, and better diabetes management. Soy is the only plant-based complete protein (meaning it contains all of the essential amino acids).
Daidzein and genistein are soy’s two big isoflavones that are beneficial antioxidants and estrogens. Soy makes a great protein source with less fat than meat. Plant-based diets are very healthy. In fact, most superfoods are plant-based.
One study on people who were overweight indicated that those who followed a low-fat, high soy protein diet lost more fat and preserved more lean muscle than the control group that didn’t have a soy-enhanced diet.[21] Soy also increases the body’s production of glucagon, which is a hormone that works to counteract insulin response, control weight, and regulate blood sugar. Glucagon slows the production of enzymes involved in making fat cells.[22]
Turkey
Studies indicate that high-protein diets like Atkins tend to have short-term weight loss. That’s a lot of effort and energy to spend on such a disciplined and restrictive diet. High-protein diets tend to be high in saturated fat and low in important nutrients.
This is not to say that healthy protein does not have its place. One study showed a high protein intake resulted in decrease in appetite and “significant weight loss.”[23] This is likely the result of increased leptin sensitivity.
The key is a healthy balance between high-quality protein like turkey and plant-based proteins. Boneless, skinless turkey has only 0.2 grams of saturated fat, compared to ham at 5.5 grams of saturated fat. Turkey is also high in vitamins B6 and B12, niacin, selenium, iron, and zinc.
Beans
Eating beans can significantly add to your fiber intake, which is important in weight loss. Fiber makes you feel full, making you less likely to binge eat. Beans are low in fat, high in healthy plant-based protein and high in good carbohydrates. A half-cup of pinto or kidney beans boasts 110 calories, 8 grams fiber, and 7 grams protein.
Adults who consume beans weigh an average of 6.6 pounds less than those who don’t, even though bean eaters consume almost 200 more calories more per day than non-bean eaters.[24] One study compared a high-fiber, low-fat diet with a regular low-fat diet and found that the high-fiber dieters had triple the weight loss.[25] Obesity can be caused by inflammation in the body, which puts you at higher risk of damage from free radicals. Beans can help protect your body and balance your metabolism.