Monotony makes you..slimmer?

This week we were discussing SENSORY SPECIFIC SATIETY in our psychology class and.. I find it fascinating!

Why do we stop eating? Because we got enough calories/feel full/got the right nutrients? Looks like we stop food intake cognitively– by knowing that we ate enough and knowing when it is appropriate to stop [studies on folks with short-term memory loss, it was found that they would eat the meal several times despite having a large meal already, when most of us would report being full at that point]

SSS within a meal

Sensory specific satiety (SSS) basically means you get tired of the taste&texture of food (studies show it happens even if you don’t swallow the food; thus it is not about getting full on calories). To be a bit more scientific in my definition: “as food is consumed, its pleasantness declines while that of other foods remains relatively unchanged”; this phenomenon of SSS leads to the termination of eating a particular food, while promoting the selection of other foods. So after being destructively full after a large meal..many would suddenly find “space” for a dessert.Image

The studies done with SSS show that if you sit down people for lunch and give them several small sandwiches with different flavors of cream cheeses, people will eat considerably more than if all those sandwiches had only one flavor (even if that flavor is a favorite of the individual). Other example is that people eat more of pasta if their bowl had more types/shapes of it. SSS does not mean that you stop wanting food- it means you don’t want more of the same food. For example, after a meal of x, y, z you are given more y… the person would say “thank you I am full”… vs. being given h– something you have not developed sensory satiety for and will still eat (therefore, all you can eat buffets are not such a wonderful idea;)

So truly, this is a great adaptation, because it motivates us to eat a variety of things. It also means that, if our meals has a large variety (in its texture & flavor) we tend to eat more. This is not particularly useful, though, in an environment where delicious food is available 24/7 and one looks to maintain a healthy weight. Think about many sauces or salad dressings that combine both strong sweet and salty tastes (thus, making sure we don’t get satiated as soon..and probably eat more).

SSS seems to work well with fats and proteins, but not so much with basic starches. What this means is that people don’t get sick of eating bread, pasta, and other starchy carbs over time. 

SSS over time…

So far I talked about short-term SSS, or satiety with one meal; however the same is true when the same food is eaten over time (i’m sure you’ve experienced this- if you keep eating the same thing daily you might get tired of it), even though long-term SSS is more complicated. The study I read*, for example, looked at eating high energy-dense snack foods for 12 weeks (hazelnuts, chocolate, potato chips). While people’s sensory-specific satiety decreased (they liked them less) over time, the desire to eat these foods didn’t…and intake increased. So habitually eating high calorie snacks could lead to higher energy intake of the snack and weight gain. You don’t really want to have a low threshold for SSS- that means you don’t get sick of foods and may overeat them more.

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Why I find this interesting? It makes me think of dieting…most dieting restricts something– carbs, fats, certain ingredients (gluten; dairy). When people see weight loss, perhaps it is because the more narrow range of foods leads them to quicker sensory satiety and then overall they just eat less? Many diet plans emphasize calculating calories is not important, as if you can eat way over your limit and not gain weight..but perhaps you naturally are lead to consume less because of the monotony of the diet? 

Another thought I had- mono-eating= eating one food at a time until you are food. The idea is- it is better for digestion, but also- looks like you would limit your food intake much more naturally (with less effort) when not having a variety in one meal. 

Overall, I think this is quite interesting. While we want a healthy variety in our diet, we probably want to concentrate it on the vegetables and other healthy foods we don’t get enough of. Variety in ice-cream and chip flavors is probably not essential at this time and age.

*Tey, S. L., Brown, R. C., Gray, A. R., Chisholm, A. W., & Delahunty, C. M. (2012). Long-term consumption of high energy-dense snack foods on sensory-specific satiety and intake. The American journal of clinical nutrition95(5), 1038-1047.

*** for more info on SSS, search for papers by Barbara Rolls.

What makes us FULL? (macronutrient perspective)

Sometime in the semester, I heard people speak about satiety (satiation is the process of feeling full & terminating food ingestion during the course of eating) in relation to protein and fat (protein apparently is more satiating, even though fat has more calories).  Feeling of fullness is important- it is one of the problems I faced as a raw vegan, which made sticking to the lifestyle very hard long-term (I was raw vegan for ~2 years).

So instead of preparing for class tomorrow, I am reading up on satiety! Some main points:

Most importantly- it’s not all about the calories, since not all calories are treated equally by the body.  The hierarchy of fullness is the following: Protein > Carbs > Fats. So, protein satiates more than carbohydrates, and fat is least satiating (which came as a surprise to me considering it has most calories per weight). High-fat foods have a weak effect on satiation.

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Within the macronutrient categories, we find differences too: not all carbs exert the same effect on satiety (fiber has been consistently shown to have a higher satiety value vs. simple sugars), and neither does fat (the medium-chain triglycerites [e.g. the wonderful coconut oil] seem to be more satiating).

Of course, people don’t eat only to get full. The number 1 reason given for eating a certain food is taste. More specifically- palatability (subjective pleasantness of food). Low-energy-dense foods tend to be less palatable, but more satiating :/

According to the article*, ideally our diet would consist of low-energy-dense foods with high palatability (unfortunately such foods are not very common). This “diet” is one low in fat, has adequate protein and fiber, and includes lots of fruits, vegetables (so food with high water content).

Of course, focusing on whole foods vs. processed makes lots & lots of sense- a whole food product takes time to chew and digests longer (satiety signals are maintained for longer).

Apart from specific studies, common sense must prevail: staying away from “fat” is not necessary (not as much as staying away from processed fat, vegetable oils, etc…), and adding great fats (e.g. avocado!) to meals is both healthy and filling (studies show that while fat on its own is least satiating, it’s power to fill us up increases when it is added to carbs).

Feeling full is important! Constantly feeling deprived could potentially lead to overeatingand more stress.

P.S. I shall probably post more on the subject of satiety later, considering I have a whole class coming up on this topic 😀

*Gerstein, D. E., Woodward-Lopez, G., Evans, A. E., Kelsey, K., & Drewnowski, A. (2004). Clarifying concepts about macronutrients’ effects on satiation and satiety. Journal of the American Dietetic Association, 104(7), 1151–3. doi:10.1016/j.jada.2004.04.027