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Ask the RCW Dietitian: Meal Replacement Products

When is it appropriate to use protein powders, shakes, and supplements to skip meals? Are these truly meal replacements or do you need to consider the caloric intake along with activity level? Are there long-term side effects with the shake crazes that are out there now such as Advocare or Isagenix?

This is a complicated question and there are lots of variables to consider. Meal replacement shakes, bars, and other products have been around for a long time. SlimFast was probably the first well-known brand, but at this point there are so many brands out there it’s not worth listing them all. There are differences from one product to the next, but most of them are generally marketed as being advantageous for weight loss when they replace a meal.

The first big question is when are they appropriate to use?

For someone on a very busy schedule who doesn’t have time to sit and eat anything, these shakes may be beneficial to get some nutrients and fuel into your body in a convenient manner. Skipping meals can negatively impact your metabolism, energy levels, and your performance in the gym. Most meal replacement shakes will give you the basics nutritionally, so they’re better than not eating when you should be.

Meal replacement products are often used as part of weight-loss regimens that feature strict calorie counting. Since the items are very uniform in size and come with a nutrition facts label, it’s easy to know how many calories they contain. Some people are able to lose weight utilizing meal-replacement shakes or bars (if they are lower in calories than the average meal they are replacing with it), but an important question to consider is this: “What am I going to do when I lose the weight and I haven’t practiced the behaviors I need to sustain the change with real food?” Unless, of course, the plan is to drink shakes in place of meals forever. My point is this: many “diets” fail in part because people do things to lose the weight that they can’t sustain once the weight is off. Meal-replacement shakes can present this same problem.

The second part of this question is regarding consideration of activity level for calorie needs in a meal replacement. A higher level of activity will result in higher overall energy needs, as well as increased protein needs to aid muscle recovery and growth. Formulas for meal replacement shakes vary greatly, so some may not be appropriate to fuel more active, athletic individuals on their own. For these individuals, it is more appropriate to utilize whole foods in addition to considering a supplemental protein source (not a meal replacement) pending their individual needs and intake.

It’s important to understand the difference between a meal replacement shake and a protein shake/supplement. A quality meal replacement product will contain a variety of nutrients intended to replicate what someone might eat at a meal. For example, a Soylent brand meal replacement shake contains around 400 calories with a blend of protein, fats, carbohydrates, vitamins, and minerals. Compare that to Optimum Nutrition’s Gold Standard 100% Whey Protein which, in one scoop, contains 24 grams of protein, 2 grams of carbohydrate, 1 gram of fat, and little in the way of vitamins and minerals. Protein powders can serve a purpose, but understand that they are different than meal replacement shakes and may not meet your needs depending on what your goals are.

The final part of this question is regarding long-term side effects of utilizing meal-replacement shakes. The first thing to consider is that, although meal-replacement shakes can offer a full variety of known macro and micronutrients, it may not be possible to distill everything we get from whole, natural food into supplement form. Our understanding of nutrition has progressed by leaps and bounds over the past hundred years and we know more than ever about our nutritional needs, but we still don’t (and may never) fully understand the complex roles of the thousands of compounds in a single food like a carrot or a spinach leaf.

The main goal of most meal-replacement regimens is to create a caloric deficit to facilitate weight loss. If this deficit is too large, however, chronic fatigue may be a potential side effect. Regardless of eating food or drinking shakes, an understanding of nutritional needs compared to intake is important.

Here are some other factors to consider related to utilization of meal replacement products:

Satiety/Fullness – Although meal replacement shakes may provide adequate calories, they often do not provide the feeling of satisfaction and fullness that can be obtained from a well-rounded meal. Feeling deprived is not a sustainable component of good nutrition, so be aware of this factor.

Cost – The cost of meal-replacement products varies greatly. A basic Ensure Plus supplement can be obtained for less than two dollars per drink if bought in bulk online, but others cost five dollars or more per shake or bar. This isn’t much different than eating lunch out every day. Consider making your own homemade meal-replacement. For example, blend two frozen bananas, two handfuls of spinach, ¾ cup of Greek yogurt, and 2 tablespoons of your favorite nut butter for a nutritious and delicious meal replacement shake that costs no more than 2-3 dollars – with real food!

Sugar and Fiber – Many meal replacements are high in sugar and low in fiber. This is in contrast to what we know to be good nutrition. Fiber is beneficial for digestive health and is linked with lower rates of many chronic diseases. If you’re considering meal replacement products, look for a product lower in sugar and higher in fiber.

In summation, there is a lot to consider regarding the role of meal replacement products. They may be helpful for some people, but there are lots of potential drawbacks. With a good understanding of portion sizes, mindful eating, and individualized nutrition needs, sticking to real food is probably a better long-term solution.

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