Fiber and protein can both work to tame your appetite. But both have a lot of other important jobs to do as well. Can we optimize for both?
Fiber and protein can both work to tame your appetite. But both have a lot of other important jobs to do as well. Can we optimize for both?
Transcript: https://nutrition-diva.simplecast.com/episodes/beef-vs-beans-a-shootout-at-the-breakfast-corral/transcript
A new study pits beans against beef to see which one keeps you full for longer. And at first, the results seem a little anticlimactic: both worked equally well. But when you look more closely at the data, it gets a little more interesting. In fact, I’ve got an idea for what they should study next!
Hello there! This is Monica Reinagel and you are listening to the Nutrition Diva podcast, a show where we take a closer look at nutrition news, research, and trends so that you can make more informed decisions about what you eat!
An interesting new study crossed my desk today, just published in the Journal of Nutrition by researchers at the University of Guelph in Canada, in which beans and beef went head to head.
But before we get to that, If you’re a subscriber, you may have noticed some extra episodes in your feeds this month. The additional shows dropping on Mondays all this month are part of our observation of Osteoporosis Awareness Month. Each week we are taking a look at different phases of life and the unique challenges and opportunities we have to build and maintain strong healthy bones. Whether you’re in midlife, or a senior, or a parent or grandparent, you’ll definitely learn some new ways to take care of your skeleton. And if you are a registered dietitian, you can even earn continuing education credits from listening to this series. Just check out any of those bonus episodes for details.
And with that, let’s dig into this new study.These researchers set out to compare how different types of breakfasts affected appetite and calorie intake later in the day. To do this, they recruited a few dozen older adults (average age around 72) and fed them three different breakfasts on separate days–a tortilla wrap filled with either black beans, kidney beans, or extra-lean ground beef.
Afterwards, the participants rated their hunger and fullness over the next three hours. They were then served an all-you-can-eat pizza lunch, and finally, they recorded everything else they ate for the rest of the day. The researchers then compared how much the participants ate, and how hungry they felt, depending on which breakfast they had eaten.
The result? Appetite ratings, lunch intake, and total daily calorie intake were essentially the same, regardless of whether the subjects ate beans or beef for breakfast. In other words, although they provide different amounts of protein and fiber, beans and beef have similar effects on appetite.
Some commentators have framed this study as a sort of showdown between protein and fiber: which one does a better job controlling appetite? But that’s not quite right. And to see why, we need to take a closer look at the nutrient profiles of these different breakfasts–and how they compare to a typical breakfast. (Because a lot of people are not eating bean OR beef wraps for breakfast.)
The biggest difference between the bean and beef breakfasts were in the amounts of fiber and protein they provided. The beef breakfast provided about 2 grams of fiber, which (unfortunately) is pretty typical for American breakfasts, while the bean breakfast provided 12 grams of fiber, about 4 times as much as a typical American breakfast.
In terms of protein, the beef wraps provided about 35 grams of protein and the bean breakfasts provided 21 grams of protein. According to dietary survey (NHANES) data, even the lower-protein breakfast provided almost twice as much protein as people in this age group typically eat at breakfast.
So, this study wasn’t really looking at high-protein vs. high-fiber breakfasts. It was comparing a high-protein breakfast to a high-fiber-moderate-protein breakfast. The typical American breakfast (which is low in both protein and fiber) wasn’t included in the comparison. And if you’ve never experimented with a higher protein breakfast, you might be pleasantly surprised at how effective it can be for managing your appetite later in the day.
As I mentioned, this study found that both beans and beef were equally effective in terms of appetite control, despite the fact that the beans were lower in protein. But of course, appetite control is not the only thing we care about.
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Both protein and fiber promote satiety, but in different, and complementary ways. Protein helps you feel full by triggering satiety hormones and causing food to move more slowly through our system. Fiber, on the other hand, works more mechanically. It slows down how fast you eat and takes up more space in your stomach—signals that also tell your brain you’re full.
And while this study adds to previous evidence suggesting that replacing some of the protein in a meal with fiber can deliver the same degree of satiety—there’s a bigger picture to consider. Satiety is just one of many things that these nutrients provide. Protein supports lean muscle mass, something that’s especially important in older adults, because of the tendency to lose muscle mass as we age. Replacing protein with fiber may not compromise satiety but could potentially impact muscle health.
Meanwhile, fiber helps to regulate blood sugar and also supports a healthy gut microbiome–which has wide-ranging effects on multiple aspects of our health. Focusing on protein at the expense of fiber could undermine gut health. And there’s one other little wrinkle I want to introduce here, and that is timing.
Our hunger and appetite do not depend exclusively on what, how much, or how recently we’ve eaten. There’s also a circadian rhythm at work. Research shows that hunger is generally lower in the morning and picks up as we go through the day, peaking in the evening. Evolutionarily, this may have helped prompt us to consume enough calories to get us through an overnight fast and keep us from waking up in the middle of the night from hunger. And it’s not just physiological hunger that peaks in the evening. Hedonic eating, or the desire to eat simply for pleasure, is also stronger in the evening–and our social rhythms may play a role in that, as well.
Given that hunger and the urge to eat for pleasure tend to peak later in the day, you might conclude that, instead of front-loading the day with tons of protein or fiber, you would be better off focusing on later meals—when appetite is naturally stronger and more difficult to manage. But, again, we need to remember that satiety is not the only thing we’re trying to optimize. Protein plays a key role in muscle protein synthesis and researchers have suggested that breakfast is exactly where we want to put our focus.
Dinner is typically our highest protein meal, providing more than enough protein to max out our muscle-building response. Breakfast, on the other hand, is typically the lowest protein meal of the day, falling well short of the amount needed to optimize muscle building. By boosting protein at breakfast.from the typical 10 grams to 30 grams, we might be able to get an additional daily bump in muscle building activity. From that perspective, the beef breakfast (or a breakfast that included a similar amount of high quality protein from any other source) might offer an advantage over the bean breakfast.
Later in the day, however, when our appetite is starting to crescendo–and our protein intakes are generally already robust, maybe that’s when adding more fiber would offer the most benefit. In other words, rather than pitting beef against beans, maybe the ideal formula is: beef for breakfast and beans for dinner!
Of course, it doesn’t have to literally be beef and beans. At breakfast, you’d want to look for a high-quality protein source that provides 25-30 grams of protein per serving (such as a 3-ounce serving of beef, chicken, fish, or tofu.). If you’re used to eating toast or cereal for breakfast, the idea of having a small piece of chicken or fish may sound kind of radical. In other cultures, however, it is completely routine. And practically speaking, heating up some leftover salmon or steak from a previous day’s lunch or dinner is just as quick–or even quicker–than making a bowl of oatmeal or a smoothie.
And then at dinner, when protein intakes tend to be higher than needed for muscle health, you can trade out some of that protein for more fiber, such as replacing some or all of the meat with a bean- or legume-based dish. Not only will your microbiome (and your cholesterol levels) benefit from that additional fiber, but it may help tame those evening munchies.
Perhaps you’ve already experimented with this type of thing. If you have any observations to share or question you’d like me to address, drop me an email me at nutrition@quickanddirtytips.com If you’d like to find out about having me speak at your next live or virtual event, you can learn more at wellnessworkshere.com
Nutrition Diva is a Quick and Dirty Tips podcast. Steve Riekeberg is our audio engineer, Brannan Goetschius provides script editing. Holly Hutchings is the Digital Operations Specialist and Morgan Christianson heads up Podcast Operations & Advertising. We get also get indispensable support from Nat Hoopes. Thanks to all of them and thanks to you for listening!