The first factor to consider is whether or not you'll be able to stick with it or whether the monotony will force you to cheat on your diet. Older adults are more likely to find satisfaction in a monotonous meal replacement diet, according to a small study published in the journal Physiology & Behavior in 2000. According to the researchers, older adults – especially men – reported far fewer food cravings throughout the 19-day-diet, which included vanilla meal-replacement shakes for seven days, followed by five days of nothing but said shakes.
Marcia Pelchat, an associate member emerita at the Monell Chemical Senses Center in Philadelphia and a co-author of the study, noted, though, that regarding breakfast nobody seems to mind monotony: “People are much more likely to eat the same thing for breakfast every day than they are for lunch or for dinner, and you might think that they get bored, but they don't.”
Emphasis on Meal “Replacement”
Additionally, what exactly are your replacing? “The question is, what would the person do if they didn't eat the bar or drink the shake? Would they go to a fast food place and have a burger, fries and sweet beverage instead of the shake? In that case, any health specialist would say, go for the shake,” Sharon Akabas, associate director of Columbia University's Institute of Human Nutrition. If you the description of your lunch includes the phrase “deep-fried,” then you're probably better off with a meal replacement shake.
Rachel Lustgarten, a registered dietitian at Weill Cornell Medical College in New York, while advocating a healthy diet of whole foods does see the advantage the meal replacements can generate: “I am not down on meal replacements entirely, particularly for people looking to lose weight or control weight. For those clients, using meal replacements can sometimes be a great way to jump-start weight loss because they are portion-controlled, high in protein and low in sugar.”
But What About the Good Bacteria and Gastrointestinal Exercise?
Charles Mueller, clinical associate professor of nutrition at New York University, notes that though your meal replacement may have the right balance of protein, carbs, and fat – and a long list of vitamins and minerals – they're not likely to contain the good bacteria needed to maintain the body's ecosystem of microorganisms.
Furthermore, Mueller says, if you're consuming meal replacement shakes (instead of bars) and consuming a mostly-liquid diet, that might have its own issues. “Your gastrointestinal tract is a big muscle that likes to work out, and it likes to push and pull food, and when it doesn't get to do that all the time on a constant basis, it's not as healthy, just like a person who stops exercising.”
So… are meal replacements for you? Let us know in the comments below!