Diet Smoothies for Lunch

A smoothie can provide a perfect lunchtime option, especially when you're trying to drop a few pounds. You don't have to spend a long time in the kitchen doing prep, which could increase your temptation to eat more than you should. Smoothies are also portable, making them an option for brown bagging at the office. A mix of fruits and milk might taste delicious, but it lacks much of the nutrition you need to keep you full and satisfied until dinner. A diet smoothie for lunch must contain healthy fats and protein too.

Fruit smoothie on a wood surface. (Image: LeszekCzerwonka/iStock/Getty Images)

Fruits Aren't Enough

When you think smoothie, you probably think "fruit." While fruit is a solid component of a diet smoothie, it shouldn't be the only ingredient. Fruits are high in sugars, albeit natural ones, which can spike your blood sugar quickly and then leave you hungry again in just an hour or so. Berries, cherries, half a banana, apple, mango, peaches or grapes are options to add, but keep the serving to 1/2 to 1 cup. Frozen fruit makes a nice addition as it thickens up the mixture to a milkshake-like consistency. To maintain the icy-cold appeal, keep the smoothie on ice or in the fridge if you make it ahead of time.

Protein and Fats for Satiety

Protein digests more slowly than the carbohydrates in fruit. It'll keep you feeling full for longer so you don't have the urge to munch after lunch. Whey, soy or rice protein powder are ways to easily blend this macronutrient into your drink. Watch that the powder you choose has no added sugar or supplements. If you prefer whole foods, try blending 1/2 to 1 cup of Greek yogurt, two tablespoons of hemp, flax or chia seeds or two tablespoons of nut butter into the mix. The seeds and nut butter are higher in calories, but full of healthy fats that also contribute to feelings of fullness. If you don't add nut butter or seeds, consider adding another source of healthy, unsaturated fat such as one-quarter of an avocado or a tablespoon of flaxseed oil.

Vegetables for Extra Fiber

You want to fit in five or more servings of veggies per day. Green, leafy vegetables are a high-quality source of vitamins, minerals, antioxidants and phytonutrients with few calories. A handful of kale, spinach and cucumbers blend well into a smoothie and add only a mild flavor. The fiber in these veggies help keep you regular and slow digestion of the smoothie so you stay full longer.

Liquid Ingredients

Fruit juice, even 100 percent versions, are high in calories and sugar. Use milk -- either cow's or an alternative type such as almond or soy -- to provide extra calcium and, in the case of cow's or soy, extra protein. Coconut water adds minimal calories and potassium, an important mineral. Water is always an option to smooth out your mixture. It may add no calories, but it also adds no flavor -- which could leave your smoothie bland and unsatisfying.