How Eating Chips With Dip Might Double Your Caloric Intake
This Week’s Research Highlight
Background
When we look at longitudinal data on the dietary habits of Americans, going back decades, one major trend emerges — people seem to consume a lot more snacks than they used to.
For instance, a comparison of food consumption patterns between 1978 and 1996 found an increase in daily energy intake of 143-268 calories, and almost all of it could be accounted for by a substantial rise in calories from snacks. More recent dietary surveys show that the role of snacking in our diet has continued to grow, now comprising around a quarter of total daily calories.
This wouldn't necessarily be a big deal, except for two things. First of all, snacks do not tend to be as nutritious as whole meals, and they're often higher in undesirable stuff, like added sugars, unhealthy fats, additives, etc.
Secondly, if snacks are added to the diet without any compensation for the calories that they provide (in other words, eating less at main meals), you're likely to see a change in energy balance, and eventually weight gain if the trend is sustained. And indeed, it is notable that these upward shifts in snacking habits have occurred in parallel with the obesity epidemic.
So it's worth taking a closer look at whether — and how — snacks could contribute to overeating.
That brings us to chips, a very popular snack food that most of us enjoy at least occasionally (myself included). Chips are often paired with dips and sauces. These condiments can vary considerably in their nutritional values, but dips in general tend to be relatively high in fat and calories. So, you might assume, logically, that adding in a dip would result in increased energy intake.
But there is another, more subtle, avenue through which adding in dip could cause you to eat more, and that has to do with the physical states of these foods. Chips, obviously, are hard and crispy. But dips, in contrast, are generally semi-solid liquids. When you eat them together, the microstructure of chips is altered in a way that may be relevant for satiation. We know that making foods softer or increasing lubrication decreases how much time you need to chew it, and thus how much time it spends in your mouth. This change in sensory exposure has been linked to increased food intake. Furthermore, just eating faster, all else being equal, is robustly associated with taking in more calories at a given meal. This has been borne out through cleverly designed experiments, which have demonstrated that simply manipulating the texture of foods to make them tougher to chew slows down the rate of eating and reduces how much people wind up consuming.
In a newly published study, researchers at Penn State decided to test how consuming chips either with or without a dip affects how much people eat (both in terms of mass and caloric intake), and to explore potential underlying mechanisms. Specifically, they wanted to see if the lubricating effect of the dip might accelerate chip consumption and thus drive overeating.
Study Design
The research team recruited 46 healthy participants for a controlled feeding experiment with a crossover design. Every subject came to the food science lab on two separate occasions, and experienced the following conditions:
- On one visit, they were presented with 70 grams of Doritos Cool Ranch Flavored Tortilla Chips (no-dip control session).
- On the other visit, they were given 70 grams of Doritos Cool Ranch Flavored Tortilla Chips, accompanied with 95 grams (4 ounces) of ranch dip.
During both sessions, they were permitted to eat as much of the test foods as they desired.
(By the way, the ultra monotonous, ranch-on-ranch flavor profile here is intentional – the researchers deliberately paired cool ranch tortilla chips with ranch dressing to control for the impact of variety, which is known to affect food intake)
Before and after, the plates of chips and cups of dip were weighed to measure how much of each the participants had consumed.
All sessions were video recorded, and analyzed subsequently to calculate the number of bites and time spent actively eating.
Results
Let’s start with the impact of dip on food intake.
When participants ate chips + dip, they ate 77% more food compared to when they ate the chips by themselves (64.3 grams versus 36.4 grams on average). In terms of calories consumed, this translated to an increase of almost 150 calories (344.6 calories with dip versus 195.1 calories without dip).
A couple of other interesting points here.
First, perhaps unsurprisingly, the participants didn't really seem to be keen on this Cool Ranch Dorito plus homemade mayo-based ranch dressing combo — they actually reported liking it less than just eating the Cool Ranch Doritos by themselves. Despite that, they still wound up eating significantly more overall when the dip was included!
However, participants on average consumed almost exactly the same number of chips regardless of whether they had dip to accompany it. So, that suggests two things.
For one, the addition of the dip did not cause participants to eat fewer chips to compensate for the extra calories conferred by the ranch, which is not encouraging from the standpoint of energy regulation. But at the same time, it also indicates that the dip was not driving subjects to eat more chips than they otherwise would have.
That brings us to the behavioral measures. The videotape analysis revealed that the amount of dip consumed did not affect the chip eating rate. This suggests that the dip was not speeding up food intake through its impact on the structure of the chips (basically, moistening it so it was easier to swallow). So, the researchers’ initial hypothesis doesn’t appear to have been supported here.
Nevertheless, participants did take in food a lot faster when they consumed chips with dip. During the chips + dip condition, participants ate at a rate of 18.7 g/minute, a 78% increase in eating rate compared to the chips only condition (10.5 g/minute).
So what's going on here? Apparently, adding dip to the chips was causing the subjects to take bigger bites.
When participants ate chips with dip, total bite size was significantly greater (3.2 g/ bite) versus chips alone (1.9 g/bite). This produced a faster rate of eating, and in turn may have contributed to greater food intake during that session.
Key Takeaways
As you might have expected, consuming chips with dip leads to greater energy intake, compared to being served chips by themselves. But not for the reasons that the researchers had anticipated. Rather than facilitating faster consumption due to altered food texture, the scoops of dip on top of the chips seemed to be causing the subjects to take bigger bites, and thus eat more than they otherwise would have.
Incidentally, this finding in itself could be quite useful for those of you who are trying to control your energy intake, and is supported by prior research showing that larger bite sizes are linked to overeating. For instance, one experiment found that using smaller spoons, to rein in how much food participants can consume in a given bite, forced them to slow down and ultimately led to them taking in fewer calories. Switching to small cutlery, like teaspoons, might be worth a try.
At first glance, the takeaway seems to be that you should avoid dips and sauces. But you can also take advantage of this phenomenon to encourage intake of the kinds of foods that you want to eat more of, like fresh vegetables. For instance, when people are presented with a snack of carrots, they also eat faster and consume more if condiments are added.
So, if you are trying to regulate energy intake and optimize nutrition, you can use dips and condiments strategically here. When snacking on vegetables, adding in a dip could help you consume more, while not taking in a massive caloric load since the vegetables have so few calories to start with.
(As an added bonus, a dip with some fat in it can dramatically enhance absorption of lipid-soluble compounds found in vegetables, like lycopene.)
Random Trivia & Weird News
Doritos were originally invented as a way to repurpose stale tortillas.
Back in the 1960s, shortly after Disneyland opened, a restaurant at the theme park called Casa de Fritos was trying to figure out what to do with a bunch of stale tortillas they had gotten from a vendor. Instead of tossing them, they decided to cut them into triangles, fry them, and then coat them in seasoning.
The chips wound up being a huge hit — so much so that Frito-Lay elected to release them nationwide in 1966. Since then, more than one hundred different flavors of Doritos have been rolled out, and they are the leader in their category, with an annual revenue of $4 billion.
Photo credit: Jim Ellwanger/Flickr Creative Commons
Random Trivia & Weird News
- Rebecca Strawbridge: Lithium, brain health, and longevity. Via Reason & Wellbeing.
- Jessica Malaty Rivera: Why does COVID-19 spike in summer? Via Science Friday.
Products We Like
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humanOS Catalog Feature of the Week
Food Environment and Weight Control
This week, we’d like to highlight one of the courses from the Ideal Weight Program, developed by our good friend Stephan Guyenet.
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Wishing you the best,
