How to build the perfect, protein-rich smoothie

Not only are smoothies convenient and tasty, but one that's high in protein will keep your appetite at bay while boosting your fat-burning hormones. Here are just a few of the many benefits of a high protein smoothie:

What protein does in the body When your stomach is empty it releases ghrelin, which travels to your brain and stimulates the desire to eat. After you consume food, your satiety centre is stimulated by hormones that are released from your stomach and intestines. The first hormone causes the pancreas to produce enzymes that break down protein, carbohydrates and fats. The second is produced lower in the gastrointestinal tract and packs an appetite-inhibiting punch, slowing the digestive process, causing us to feel full for longer.

Bottom line: Protein consumption causes the release of this second hormone, so eating protein regularly throughout the day will keep your appetite under control. This is also the reason you should eat your protein first at mealtime, versus your carbs. When you are crunched for time, a protein smoothie will have the same effect on keeping your tummy satisfied, all the while improving your body composition.

Whey manages insulin levels The metabolic benefits of a whey protein isolate are vast. The good news is that this body slimming secret is easily available in almost every health food store. According to a study published in the British Journal of Nutrition, whey protein isolate renders a powerful effect on body composition, lipids, insulin and glucose in overweight and obese individuals. Researchers found that subjects using a whey isolate (versus a mixed or casein protein powder, which unlike whey isolate, is not as highly absorbable and is more allergenic) experienced a significant decrease in total cholesterol and LDL cholesterol over 12 weeks. Fasting insulin levels also dropped in the whey group compared to their counterparts. Another study in the American Journal of Clinical Nutrition found that when whey protein is ingested before a meal it reduces the overall food intake as well as pre- and post-meal satiety.

Bottom line: I recommend whey protein in your mid-morning and mid-afternoon snacks. This “secret ingredient” will reduce your appetite at lunch and dinner. Moreover, it also lowers post-meal glucose and insulin response. Click here for a few more do’s and don’ts for controlling your appetite.

Most powders are high in protein, low in calories A good whey protein isolate is top on my list of insulin sensitizing, appetite controlling superfoods. However, there are many other options to power up your smoothies with a healthy dose of protein. When choosing whey, be sure to select an isolate, versus a mixed whey blend or whey concentrate, as these contain lactose and can upset your stomach.

Bottom line: A good rule of thumb when selecting a protein powder is to look at the serving size listed on the label. Most protein powders come in a 30g serving. Within that serving size, make sure that you're getting at least 20-25g of protein, which indicates that there are less fillers or carbs than a competing product that may have only 15-18g of protein for a 30g serving. And of course, be sure to choose a product free of artificial sweeteners and added sugars.

They offer options While soy is a popular alternative to whey, having it more than once a day can be problematic due to the phytoestrogens. When consumed in smaller amounts, the phytoestrogens in soy can be protective. However, when consumed in excess these same phytoestrogens can be harmful. Rice or bean protein powders are a good choice for individuals with intolerances or sensitivity to dairy (whey protein is made from dairy) or to soy. Some common vegan sources of protein include: brown rice protein, hemp protein, pea fiber protein and pumpkin seed protein. I find the most common complaint with these products is the taste as they are grittier than a whey protein. They've come a long way however, and there are plenty of vegan products on the market that use a blend of these sources (including Vega, Genuine Health and Progressive).

Bottom line: It’s really just a matter of trial and error to see which one suits your tastebuds and dietary restrictions.

How build the perfect smoothie To take advantage of the many benefits listed above, in my opinion your smoothie should have five components:

1. Protein powder: whey, soy, or a mixed vegan source 2. A sugar free fat source: one tbsp of coconut oil, chopped nuts or natural nut butter 3. A non-psyllium fibre: one tbsp chia seeds, ground flaxseed or preferred fibre 4. A low glycemic fruit: ½ – 1 cup berries or ½ banana 5. A liquid: water, unsweetened almond milk, or even non-fat or Greek yogurt

Try adding one of these to change up your daily smoothie and for added benefits: greens powder, cinnamon, unsweetened cocoa powder, inositol powder (for a mood boost), or glutamine (to soothe your stomach).

Get more refreshing smoothie recipes.

Natasha Turner, N.D. is a naturopathic doctor, Chatelaine magazine columnist, and author of the bestselling books The Hormone Diet and The Supercharged Hormone Diet. Her newest release, The Carb Sensitivity Program, is now available across Canada. She is also the founder of the Toronto-based Clear Medicine Wellness Boutique. For more wellness advice from Natasha Turner, click here.