1. A low carbohydrate diet will help me lose weight :
Weight loss is greatly determined by calorie intake. If you’re in a calorie deficit state (consuming less calories than you’re expending), you will most likely lose weight. So, whether these calories come from protein, carbohydrates or fats will not make much difference.
However, studies do show that satiety plays a big role in weight management - foods that make you feel "full" will help you reduce the overall calories you consume. Some studies show that certain food groups play a bigger role in satiety than others. These groups include lean protein (beans, meat, nuts), high fibre carbohydrates¹ (whole grains), and vegetables.
2. Quinoa is a good source of protein:
There is a LOT of misinformation about quinoa’s nutritional value circulating on the web. Is quinoa really a good source of protein? You’ll get around 3.22 grams of protein in half a cup (1 serving) of cooked quinoa. This places it a little higher than rice (2.69g) and lower than spaghetti (4.29g).2 So, calling quinoa a “good source” of protein is questionable. By definition, a “good source of protein” must meet 10% - 19% of the recommended Daily Value per serving of protein. At the bare minimum, a “good source of protein” should provide 4.6g per serving for the average adult female and 5.6g per serving for the average adult male.4 Quinoa doesn’t make the cut.
So why is there so much hype around quinoa’s protein content? Most sources of carbohydrates (maize, grains, pulses and starchy vegetables) do not contain all 8 essential amino acids (building blocks of protein that the body cannot synthesize on it’s own). Quinoa on the other hand has a more complete amino acid profile5 (including higher amounts of lysine which is rare in other grains)6. However, there is little scientific literature to confirm the dietary and health significance of quinoa’s more complete amino acid profile.
Therefore it is important to not over rely on quinoa as a staple but rather eat it as a part of an overall balanced diet.
3. Gluten-free is healthy, right?
Just because something is labeled gluten free doesn’t mean it is healthy. Gluten is a protein found in wheat, rye, barley and any other foods/drinks made of these ingredients (beer, pasta, bread, etc.). The gluten free diet is mostly recommended to people with celiac disease: a digestive disorder that causes damage to the lining of the small intestine when gluten is consumed. However, for the average person, the gluten-free label does not serve as the healthy seal of approval to any particular food item. For example, a box of cereal that is labeled gluten-free may still be calorie-dense with added sugars, artificial colouring and preservatives.
4. Eating more complex carbohydrate is the way to go:
Complex carbohydrates are composed of longer chains of sugar molecules. In contrast with simple carbohydrates (i.e. table sugar), they are not as easily digested and absorbed in the body, resulting in lower blood sugar spikes after meals. Furthermore, since complex carbs are usually less refined, they tend to have more vitamins, minerals and dietary fibre than simple carbohydrates.
However, not all complex carbohydrates are actually “healthy.” A lot of nutrition sources online tend to paint all complex carbohydrates with broad strokes despite the differences that lie within the category. For example, although white bread is considered a complex carbohydrate, it is stripped of most it's nutrients. A good reference for the healthiness of carbohydrates is The Glycemic Index (GI) - an index of how food affects blood sugar and insulin levels. Low GI foods such as whole grains and beans are digested and absorbed more slowly in our stomach, thus preventing blood sugar and insulin spikes throughout the day.
5. Whole grain bread has less calories than white bread :
White and whole grain bread have very little to no difference in calories. If we take a commonly known brand like Demspter’s you’ll find that both whole wheat and white bread have 85 calories per slice.
The differences in nutritional value between white and whole wheat bread have more to do with the amount of dietary fibre, vitamins and minerals - nutrients that play little to no role in the calorie content of bread. The difference lies in the bran and germ (outer layer) of the wheat grain used to make bread. White bread is stripped of it’s nutrient rich outer layer, thus has a lighter colour and lower amount of all measured vitamins, minerals and dietary fibre. It is however important to note that commercially produced whole wheat breads may have added salt and sugar to compensate for perceived taste.
¹ Salvin, JL. "Dietary fibre and body weight." Nutrition. 2005 Mar; 21(3):411-8. Accessed on 2014 Oct 3: http://www.ncbi.nlm.nih.gov/pubmed/15797686
² Wycherley, TP, et al. "Effects of energy-restricted high-protein, low-fat compared with standard-protein, low-fat diets: a meta-analysis of randomized controlled trials." Am J Clin Nutr. 2012 Dec;96(6):1281-98. accessed on 2014 Oct 2: http://www.ncbi.nlm.nih.gov/pubmed/23097268
3Canadian Nutrient File Nutrition Database: http://webprod3.hc-sc.gc.ca/cnf-fce/index-eng.jsp
4"Nutrition For Everyone: Protein." Centre for Disease Control and Prevention. 2012 Oct 4. Accessed on 2014 Oct 3: http://www.cdc.gov/nutrition/everyone/basics/protein.html#How%20much%20protein
5 "Quinoa: Nutritional Value." 2013 International Year of Quinoa Secretariat, FAO.2013. Accessed on 2014 Oct 2: http://www.fao.org/quinoa-2013/what-is-quinoa/nutritional-value/en/
6Young, Vernon and Pelet, Petr. "Plant proteins in relation to human nutrition and amino acid nutrition." Am J Clin Nutr . 1994 May; 59(5):203S-1212S. Accessed on 2014 Oct 2:http://ajcn.nutrition.org/content/59/5/1203S.full.pdf