Food and Health

What makes us FULL? (macronutrient perspective)

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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

SPICE up your health!

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Could SPICY FOOD make you HEALTHIER!?

While spicy foods are not particularly pleasant to the taste (the sensation they can create can be even that of pain) many people love spicy food! Indeed, spices have been highly valued and fought for throughout history! So other than enhancing the taste of food, perhaps there are other more potent reasons for their importance throughout the world?

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I’m reading a fascinating study* on the subject, and the authors hypothesize that adding spices to food is beneficial since they contain substances that inhibit or kill food-spoilage microorganisms (we know certain spices have antioxidant & antibacterial properties; others are powerful fungicides).

In short, the authors looked at traditional cookbooks, spices used in meat-based dishes, and country’s climate (since meat products in hot temperatures would spoil fastest).

The most used spices for the ~4,580 recipes analyzed were onion and pepper, followed by garlic, capsicums, lemon/lime juice, parsley, ginger, and bay leaf. The average spice was found to inhibit ~ 67% of bacteria (garlic, onion, allspice, and oregano inhibit EVERY bacterium they’ve been tested on!). It was found that more powerful spices were used more frequently in hotter climates= recipes from those countries have more antibacterial potential! Lemon and lime juice use appears to be strange- it is used a lot, while it has one of the lowest effects against bacteria. These juices, however, are syngergists (as well as pepper)! They act synergistically to enhance antibacterial effects of other spices.

HMMM…

Now as I was reading this, I thought- maybe hotter countries simply have more spices growing there? The authors found out that there was no relationship between a country’s mean annual temperature & number of spice plant species growing there.

Another problem I imagined- what about cooking? Perhaps heat destroys some of the antibacterial and other effects of spices? Turns out spices are thermostable and have similar effect even after steam-distillation.Image

INTERESTING fact I didn’t know- plant secondary compounds & essential oils can contain mutagenic, carcinogenic, and allergenic effects.. and while protecting oneself from food-borne illnesses outweighs the dangers of these chemicals, it would explain why kids and some pregnant women might dislike spices. [in the modern obesogenic food environment with french fries and twinkies, potentially negative health of spices should not be on top of our concern list]. Also important- medicine is pretty much a low dose of poison…so spices have been used to counteract ailments of all sorts (e.g. garlic for pneumonia, worms, etc). Animals are capable of self-medicating with strong-tasting vegetation as well.

In CONCLUSION, the authors believe that the main reason for spicy foods is to take advantage of the antimicrobial actions of the secondary compounds in plants… which contributes to survival, health, and reproduction. Therefore, many people (especially in hot climates) prefer spicy food. If you like it HOT- GOOD FOR YOU 😀

* Billing, J., & Sherman, P. W. (1998). Antimicrobial functions of spices: why some like it hot. Quarterly Review of Biology, 3-49.

p.s. this of course is not to be the only explanation why spicy foods are liked, there is also social learning and what not 😉

Gluten Free for a happier life!?

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So Gluten Free is a rather growing popular dietary approach. Obviously, those suffering from celiac disease absolutely need to avoid gluten, and some believe many people have some degree of intolerance to gluten…others claim our bodies are simply not designed to process it.

I am currently working on a literature review on functional foods (including GF) and am reflecting on my own recent purchase of GF bread.

In fact, I do not eat bread (a diet food practice I brought with me from Ukraine), and yet I got GF bread for the house…

Why do we think GF is healthier? Is it simply because the “free” part is associated with other “free from” foods that are supposedly healthier? (fat free! sugar free!) Usually “FREE” would mean something bad has been removed from the product.

Is it because we see many celebrities adopt the lifestyle, lose weight, look chic, and twit about it? They must know what they’re doing…(?)

Is it our beliefs about the nature of health and the way our body evolved? I’ve heard many people quote the “10,000 year” point- that agriculture is rather recent and our bodies have not adopted to processing grains and gluten (this is inspired by the paleo information).

Does it matter? The truth is many people feel better when they go GF- more energy, better digestion, and more. I personally doubt it is the gluten primarily (unless someone truly is sensitive!?)- many going GF simultaneously improve their diet and lifestyle. Indeed, many poeple going GF are health-conscious individuals in general (health consciousness is the degree to which one plays an active role in maintaining their health).  It is obvious that in the modern civilized world the pursuit of health, responsibility for one’s well-being and self-improvement are central themes.

I personally avoid gluten on a typical day- I already am not a fan of grain and breads (my Ukrainian family&friends always emphasized getting rid of baked items to maintain weight)…besides, due to gluten’s fantastic binding ability, it is added to most foods and it could be its unprecedented overconsumption in the last several decades that makes us sensitive.

Eat healthy for healthy kids!

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Looks like a varied healthy diet is important before a kid is even able to eat solid foods. Specifically, it is important for pregnant and breastfeeding mothers, since a child’s first experiences of flavor occurs prior to birth through milk feeding and amniotic fluid in utero.

SO eating a variety of vegetables and fruits influences acceptance of these foods at the weaning stage (~5.7 months).

Breastfeeding is crucial (vs. formula-feeding), since it prepares kids for novel flavors through the mother’s diet being transmitted to milk [Flavors so far known to be transmitted through breast milk are garlic, ethanol, carrot, mint, blue cheese, and cigarettes]. If formula-feeding is the only option, it is important to switch formula flavors and types to allow for variety.

Conclusion: varied diet in pregnancy and during breastfeeding is recommended.  Some suggest that up to 6 month is the period we are most sensitive at for introduction of different flavours..and that we are never again as open to new experiences!*

Note: repeated exposure to one flavor can become monotonous and actually decrease liking in a child.. so that would be counterproductive (again, variety is good!).

Lastly..

Being overweight or having a “junk” diet (for mothers) can be potentially detrimental for kids.

1. Being overweight/obese is a risk.. The problem- overeating and obesity during pregnancy lead to in utero overnutrition..and can cause the development of obesity in the adult offspring (even when the child had normal feeding and lactation).

During pregnancy leptin resistance and hyperphagia occur, which lead to increased deposition of fat.. In lean individuals this is a great adaptation allowing mothers to store energy in preparation for lactation (a high metabolic demand activity).. But in the current “obesogenic” environment this adaptation would make it hard for women to regulate their food intake (especially those predisposed to obesity).**

2. While I haven’t found a study on humans, studies on rats show that rats born to mothers fed junk food during gestation & lactation developed an increased preference for sugary, fatty, and salty foods; they also exhibited increased weight and BMI. Data from numerous studies shows that maternal junk food diet can change the ofsprings’ epigenetic marks related with long-term changes in gene expression (opiods & dopamine) and behavior (stronger preferences for palatable foods- sugar/fat/salt).***

* Article doi:10.1016/j.appet.2011.05.317

** Article doi: 10.1210/en.2008-1106

*** Article doi:10.1210/en.2010-050

Loving it healthy!

MariyaKLeave a comment

Reading yet more articles on the psychology of eating…

How do we learn to like certain foods?

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Well, we learn when it makes us feel good (we feel full, the sweet taste is pleasant), because other people do so (we model behavior of others, eat what our culture things is appropriate), and because it’s something we’ve eaten many times (we’re exposed to a certain food since childhood).

Food neophobia is the fear of new foods in kids (starts ~ age 2). It’s an important trait since it serves a protective function (you can get poisoned by eating unknown foods), but at this time in history with diverse food environment it might limit kids’ diet for the worst.

Learning through exposure (repeated tasting) is a way to make young children eat food that they don’t seem to like. [Between 50-60% of variance in preference for foods in 4-year olds is explained by its sweetness and degree of familiarity!]

For a 2 year old, ~10 attempts might be necessary to make them like a new food (usually vegetable 🙂 It’s important to space these attempts and be persistent (most parents just give up after trying to give one food several times). So e.g. you can give a red pepper in small portions daily over the course of the week and eventually your kid will like it!

The number of attempts goes up with age ( 4-year old- ~15 attempts; 10-year old- up to twenty exposures to the food may be necessary).

You want your kid to enjoy vegetables later in life- start them early by giving it to them at a young age and don’t give up 😀