1.) It Contains Way Too Many Calories
The idea behind following a smoothie diet is twofold:
- To provide your body with all of the protein and nutrients it needs to function well.
- To guard your lean muscle mass, while simultaneously cutting back on calories. This encourages your body to tap into stored fat for energy. Adding too many calorie-dense foods to your smoothie defeats the purpose. I advise my patients not to exceed 370 calories per smoothie.
- Keep an eye on serving size and watch for calorie-dense ingredients, such as yogurt, milk, nut butters, seeds, and avocado.
- Make your smoothies at home. Most fast food smoothies contain far more than a single serving. For example, one large Banana Berry Jamba Juice Smoothie contains more than 500 calories and 100 grams of sugar.
2.) You Only Use Whey Protein
There’s a reason this kind of protein is favored by athletes and dieters. Whey protein contains particularly high levels of the amino acid leucine, which stimulates the protein synthesis that protects and builds up lean muscle tissue. Since the speed of our metabolisms is primarily dependent on how much lean muscle mass we have, whey is an excellent choice for guarding muscle and accelerating your metabolic rate.
That being said, whey protein digests very quickly, often leaving us feeling hungry not long after consumption. If weight loss is your goal, you’ll need to add some different protein sources to your smoothie diet.
- Mix your whey protein with another source of protein. I offer a protein powder that combines the power of whey with casein. Casein, unlike whey, digests slowly, over the course of several hours, keeping you feeling full longer between meals.
- Make sure to include a serving of fresh fruits and veggies in your smoothie to add plenty of dietary fiber, which also contributes to satiety.
3.) You Add Sweeteners
Most dieters are aware that adding sugar or high fructose corn syrup to a smoothie will defeat any weight loss advantage a smoothie diet may offer. However, many people add ingredients that masquerade as being healthy, but actually contain high amounts of sugar. Or, they contain artificial sweeteners that trigger cravings for more calories and interfere with fat metabolism. These foods include:
- Flavored yogurt
- Fruit juice (even 100% natural)
- Frozen yogurt
- Artificial sweeteners
- Canned fruit
- Dried fruit
- Sweetened protein powder
- Maple syrup
- Sweeten with fresh fruits only. A banana or a handful of berries add plenty of natural sweetness.
- Try to add all whole food ingredients to your smoothie, along with a high quality protein powder.
4.) You Don’t Add Enough Protein
I’ve seen many smoothie recipes online that sound healthy in theory, but in reality will not provide the protein that your body needs to stay full between meals. Some of those smoothies are made of fruits, vegetables, and a liquid base alone. In order for a protein smoothie to keep your metabolism functioning optimally, aim for around 20 grams of protein per smoothie.
- Beware of smoothie recipes that are really just a blended juice. Smoothies should include a protein powder or other substantial protein source.
- If you prefer not to use protein powder, a cup of nonfat, unsweetened Greek yogurt works really well.
- Check out my protein smoothie recipes, featuring dozens of different flavors for every taste.
5.) You Aren’t Pairing Your Smoothie Diet With Exercise
Your body processes sugar more effectively when it’s physically active. While you shouldn’t be including any added sugars in your smoothie diet, any smoothie will contain a reasonable amount of natural fructose from the fruits that you include. To minimize the effect of experiencing a blood sugar spike, add some movement to your daily routine and strength train at least twice per week.
- Only include 1-2 servings of fresh fruit per smoothie.
- Include a serving of a high fiber vegetable in your smoothie.
- Make physical activity part of your daily routine, with an emphasis on strength training.
6.) You’re Drinking the Same Smoothie Every Day.
One of the reasons we can experience hunger is due to malnourishment. When the body senses that it is deficient in a nutrient that it can only get through foods, it sends out hunger signals. This is true even when plenty of calories have been consumed for the day.
Some of my patients find one or two smoothie recipes they really like and stick with those over and over again. While the smoothie may be a healthy choice in and of itself, your body needs a range of fresh vegetables and fruits to provide different nutritional needs.
- Find at least five different smoothie recipes you like featuring fruits and vegetables of different colors. I advise my patients to “eat the rainbow” and include produce in greens, oranges, reds, blues, and whites.
- Do the same with your whole food meals.