Chia Seeds as Weight Loss Aid – Is There Truth to the Claims?
Weight loss gurus across the globe are touting the weight loss benefits of chia seeds, but is there any scientific proof to back up these claims? In this article, we first look at the potential use of chia seeds as a fat-burning food from a theoretical point of view. Then, we delve into scientific studies that have actually tested the potential weight loss benefits of eating chia seeds in practice.
The Theory
Chia gel to prevent overeating and insulin spikes
If you mix chia seeds with water or juice and let the mixture stand for 10 to 15 minutes, the seeds will absorb the liquid and you will get a gel-like substance. Taking a few spoonfuls of this edible gel before a meal will help promote a feeling of fullness in your stomach, thereby reducing the risk of overeating.
Furthermore, eating soaked chia seeds helps slow down your digestion and keep your blood sugar levels on an even keel. Stable blood sugar levels are important for successful weight loss for two reasons: first, they help reduce cravings (especially for sugary foods) and binge eating, and second, they help keep your insulin production under control. Insulin enables your body to use glucose as a source of energy, but excessive amounts of insulin promote fat storage in the body.
Calcium for energy metabolism
Chia seeds are a rich source of calcium, with two tablespoons of whole chia seeds providing more than 130 milligrams of calcium. This amount corresponds to over 13% of the daily value (DV) for calcium. Although best known for its role in maintaining healthy bones, calcium can also offer weight loss benefits. Calcium plays a role in energy metabolism, and it may help regulate body composition and reduce body fat percentage. One study found that a 1-gram increase in daily calcium intake led to an average decrease of 8 kilograms (17.6 pounds) in body weight.
Zinc to curb cravings
Although chia seeds don't contain as much zinc as some other seeds (such as sesame seeds, flaxseeds and pumpkin seeds) they are still a good source of zinc. Zinc in chia seeds may help you lose weight if you have been diagnosed with a zinc deficiency. Research shows that by increasing their zinc intake, zinc deficient individuals can boost their levels of circulating leptin.
Leptin is a hormone that plays a key role in regulating the body's energy expenditure, fat storage, and appetite. It sends signals to the brain telling when you should feel full and stop eating. Some researchers even claim that suboptimal leptin levels are the primary cause of food cravings and overeating.
More energy = more energy burned
According to Spanish manuscripts, the Aztecs ate chia seeds to improve their stamina and endurance. They called chia the "running food" as eating just a handful of these extraordinary seeds would give Aztec messengers so much energy that they could run all day. Today, adecdotal claims of chia's energy-boosting properties abound, and considering the impressive nutritional profile of whole chia seeds, it seems plausible that there is truth to the claims of chia's energy-boosting properties.
Now, people who feel full of energy are more likely to head to the gym or go for a run than people who always feel tired. Therefore, more energy tends to lead to more activities that burn calories, and thus can help you lose weight.
The Studies
Animal studies suggest chia may promote weight loss
Based on animal studies, it appears that the weight loss claims made about chia seeds may indeed hold some truth. A 2008 study published in the British Journal of Nutrition found that chia seeds were capable of preventing the onset of insulin resistance in dyslipaemic rats (dyslipidemia refers to an abnormal amount of lipids in the blood). Insulin resistance has been linked to weight gain in both animals and humans.
In addition, the rats that received chia experienced a reduction in viscal adiposity, also known as intra-abdominal fat. This type of abdominal fat has been linked to many obesity-related diseases such as type 2 diabetes and inflammatory diseases.
Another animal study found that broiler chicks that were fed a diet containing chia seeds for 49 days had a lower body weight, compared to the control. Reductions of up to 6.2% in body weight were recorded in the test group that received the highest amount of chia (20% of the diet). These study findings were published in Poultry Science in 2002.
Human studies found no weight loss benefit
Research on the potential weight loss effects of chia seeds on humans is still very limited, but the studies that do exist, show no weight loss benefit resulting from eating chia seeds.
A 2007 study published in Diabetes Care found that long-term supplementation with chia seeds reduced several risk factors for cardiovascular disease, such as systolic blood pressure and high-sensitivity C-reactive protein, but did not result in weight loss in the test group, which consisted of men and women with type 2 diabetes. The daily dose of chia seeds used in this study was around 37 grams, which is equivalent to three heaping tablespoons of dried chia seeds.
A more recent study, published in Nutrition Research in 2009, also found no weight loss benefit of chia seeds in overweight men and women who consumed 50 grams of chia seeds per day for 12 weeks. In addition, this study found no changes in blood pressure and other markers of cardiovascular disease risk – which contradicts the findings of some other studies done on chia seeds and cardiovascular health. However, it has been suggested that, although the authors of this study deemed the large standard deviations for the key measurements statistically insignificant, there may have been some confounding external factors that may have influenced the results.
The Bottom Line
One thing seems clear: chia seeds are no magic bullet for weight loss. However, they do offer a broad range of nutrients, many of which are known to support weight loss efforts when all other components of the weight loss equation are in place. This means eating a balanced diet rich in fresh, unprocessed foods; avoiding junk food and hidden calories; and exercising regularly.
And finally, even if they won't act as a miraculous weight loss food, chia seeds are still a nutritious food full of health boosting nutrients and phytochemicals. To learn more about the health benefits of chia seeds, check out the article Why Chia Seeds Are Good for You (and the Healthiest Way to Eat Them).