Do you think your portion sizes at mealtimes are just the right size for you and if you ate any less you'd be hungry and unsatisfied? Are you sure? There's some stunning research out there showing that how much we eat is strongly impacted by external factors, and it suggests that by tweaking some of our practices we could eat less without feeling like we're missing out, which could result in some major benefits-- for our wallets, for our health, and for the planet.
It shouldn't be surprising to suggest that we could be eating less, considering that today's Americans eat more food in larger portions than we did just a couple of decades ago, and more than people in many other countries (like France) currently do. If those amounts work perfectly well for others, they should work for us. So why don't we just eat less? The answer appears to be connected to the size of the portions we're presented/serve ourselves, and the pace at which we eat our food.
The size of the portions we eat both at home and in fast-food restaurants has been growing and (unsurprisingly) the amount that we think of as the typical or appropriate portion has grown along with it. That would be fine if we typically just stopped eating when we're full-- but the evidence strongly suggests that we don't. (This seems to change in early childhood; in one study, three-year-olds ate the same amount regardless of portion size, but five-year-olds ate more when presented with more food.) From drinking more soup from a bowl that secretly refills itself, to eating more (stale!) popcorn from a giant tub than a smaller one, the basic human decision about how much food we should put in our body is apparently highly dependent on external cues. (For Americans especially: a recent survey found that Parisians say they stop eating when they feel full, while Chicagoans typically say they stop based on when their plate is empty, others at the table stop eating, their TV show is over, or other external factors.)
And yet, those who eat more due to external cues are often exactly as satisfied and full as those who eat less. Those bottomless-bowl eaters, who on average ate 73% more soup than those with regular bowls, didn't end up feeling more sated than their lighter-eating counterparts. Neither was there a difference in reported fullness between subjects in another study who ate more macaroni and cheese when more was presented to them, or those in yet another study where subjects ate more from a 12-inch than an 8-inch sub sandwich.
Obviously there's a tipping point-- at some point, eating too little will leave you hungry-- but the question is, where on the spectrum are you? Are you sure that you're eating the smallest amounts that are right for you, or are you responding to external cues and then falsely assuming that because you feel full (and not over-full) you must have picked the right amount?
Why not try altering the external cues to see what'll happen? Serve yourself smaller portions from smaller serving dishes onto smaller plates or bowls. Leave the evidence of what you've eaten-- the chicken bones or candy wrappers or peanut shells-- in front of you rather than out of sight; and keep the serving container out of sight and out of reach so you have to work to get it. Make unit bias work for you by pre-defining your own portions-- divide up your food into individual baggies or tupperware so that you're more likely to later conclude that the portion you see is the amount that's just right for you.
And you can work on shifting from external to internal cues, too, by trying to eat slowly and pay attention to your own sense of fullness. In one study, participants who were served a giant plate of spaghetti were asked to either eat quickly or slowly, and to eat until they felt comfortably full. The slow eaters ended up eating less, yet they were actually more satisfied and less hungry-- both immediately after eating and an hour later-- than the quick eaters who ate more food!
So try this: start serving yourself smaller portions. Eat slowly and savor your food. Give yourself plenty of time to register how full you are (about 20 minutes is the typical estimate.) And if you're still hungry after all that, you can always go back for more. But instead, you may find the quantity of food you eat diminishes... and as a result, you're probably saving money, improving your health, and easing your impact on the environment.
Have you tried to eat smaller portions, eat more slowly, or used other methods to eat less and still be satisfied? How'd it go? Do you know of any other tips and tricks to try along these lines?