Thanks - that was really fascinating.

I was going to mention this as well! It was interesting to see the varying degrees to which thin people gained weight when they were given large amounts of food to consume.

I've been searching desperately for the study regarding hunger that was conducted with five year olds and I can't find it. From memory they had five year olds eat until full. They all indicated they were full from a specific visual scale. Then they had them color and placed a plate of cookies on the table. Some of the full children didn't even touch the plate of cookies while others ate them even when they were full. I can't remember what the conclusion was regarding the difference in behavior, but I did find it interesting that there was such a clear distinction from a young age.

I tend to go straight to scientific studies regarding factors that lead to obesity. There is plenty of scientific evidence that suggests that genetic factors are related to fat gain and loss, hunger, and how our bodies process foods. There are even studies that indicate that people that were overweight would have to eat less than someone who was always thin to maintain the same body weight. There are studies that show that people's bodies react differently to exercise. Adding on to genetics are all the medical conditions individuals can have or necessary medicines for medical conditions that effect fat gain and/or loss.

If you tend to focus on these things it can be pretty depressing. I think though we have to each come to terms with the fact that regardless of genes, medical conditions, medications, and our bodies response to exercise among other things that are always things that we CAN control that will allow us to lose weight. But also because of their various factors, we should be realistic about our expectations for weight loss and ideal body weight. It is better to focus on the things we can change and let go of the things beyond our control.

That's been my experience. Though I still occasionally crave things I don't eat like cake batter ice cream or teriyaki, many of my daily cravings are things like a rib eye steak or blueberries and cream (both of which I can and do eat regularly). When I haven't had a lot of roughage, I find myself craving salad, too!

And I had something happen this week that had me thinking about 'naturally thin'. My mother in law has been athletic and svelte her whole life. She's in great shape and seems to never struggle with food OR energy to be outside and moving around (my hobbies are the much more sedentary type, like knitting and reading, as opposed to triathlons and gardening like her).

But she spent a whole season out of town, living in a hotel while the state legislature was in session, and the long hours of committees, constant travel, and sub par food apparently even affected her! She commented that she wished she could do some meetings standing up (like she had seen in a TED talk) and that she'd put on ten pounds during the months she was gone and couldn't wait to get it off.

This is a womani would have sworn was completely intuitive in all her eating and activity, and didn't even own a scale. And yet not only did she have issues maintaining her weight in a stressful situation, she actually commented on needing to work it back off. I had always just assumed she didn't struggle with these things, because of the appearances and lack of issues in the past. But it looks like at least a small amount of awareness and normal life habits she has chosen are what help her stay trim, not just some miracle metabolism. While she is still definitely genetically predisposed to leanness, as her family and own post-menopausal body has clearly demonstrated, there is a level of choice and response I hadn't seen in her until now. She's naturally thin, but that doesn't mean thoughtlessly, effortlessly thin.

It was kind of eye opening, even though I always knew most thin folks put at least some effort, conscious or otherwise, into maintaining, it was a great illustration of the principle at a time when this forum had it on my mind. Thus, I had to share :D

Sometimes we assume that naturally thin people don't have to put any thought into what they're doing but actually it requires some effort to stay naturally thin. The difference is that the effort they put into maintaining their health is not a struggle for them, it's matter of fact - like brushing your teeth. You don't have to constantly remember to brush your teeth it's just a habit you've formed since really young. Same thing with nutrition, they just KNOW that eating a box of cookies is out of the question where as we overweight people feel the need to contemplate a box of cookies on a regular basis.

I have an eating issue and I'm wondering if others have that same issue. I will eat when I'm not actually hungry if I think I'm going to be in a situation where there will not be any food available to me for a while. For example, last night we went out for dinner and I ordered a sandwich but only ate half of it. I brought it home, planning on saving it for lunch today, but when my husband decided we would go to watch my grandson's baseball game I gobbled up the other half of my sandwich. I was not hungry, but didn't know if there would be a concession stand etc IF I got hungry. I notice that I do that in many situations. Before I retired, I would always eat something on my morning break, not because I was hungry, but because I wasn't sure I could go until lunch without getting hungry. It really wouldn't have hurt me to be a little hungry for a while before lunch.

I didn't think I would ever get my husband to use fat free milk, but I did the same thing....did it gradually. One day recently he ran to the convenience store for milk and accidentally grabbed whole milk. He was eating cereal and he said "There's something wrong with this milk." He smelled it and it smelled ok but he was going to dump it out until he noticed the label. He could not stand whole milk anymore! LOL

Oh yes. I do that. Many times I will eat a whole meal in secret right before going out to dinner. I do it if I know I'm going to dinner with people who are vegetarians or vegan, that I just KNOW are going to eat like a bird. Their eating makes me nervous and extremely hungry and I feel like a fat slob if I order a cheeseburger and fries. Sometimes I wonder if they're all pre eating their meals before going out for a meal lol.

I do this too. It is a habit I have tried to get rid of for decades because really I am fine on occasions when I do get hungry & am not anywhere I can really eat. There is never an emergency to eat for me. I can wait but I always feel worried I might get hungry.

This is why I don't like the term "naturally thin" as everyone IMO will be either thin or not thin depending on circumstances & behavior.

That study was actually described in the documentary referenced above ("Why are thin people not fat"). As far as I'm concerned it was the most interesting part of the documentary. You could see some kids pushing their plates away in annoyance, while others kept eating "just because." (Well, just because it was yummy stuff like chocolate and cookies.) My hunch has always been that this variable (i.e., likelihood of continuing to eat after reaching physiological satiety) contributes the most to differences in girth among humans.

F.

That documentary on YouTube was really interesting, but even after seeing all that, I still have one question: If these differences mainly are genetic (i.e., our body has a natural "set point"), why weren't those differences as pronounced in the 40's or 50's, for instance?

I'm far too young to know much about the 40s and 50s, but I would think a major difference is in "normal" portions then vs. "normal" portions now. There are several good videos on the topic on Youtube.

Yes, I know, but what I gleaned from the documentary is that some are genetically predisposed to be thin while others are not. As such, it seems like regardless of how much food is around, those who are genetically predisposed to be thin would still be thin because they wouldn't want to overeat no matter what foods are abundant----according to the documentary. Even if people who are genetically predisposed to be fat get fatter because of big portions, shouldn't those genetically predisposed to be thin stay the same? Why are the numbers of obese people higher now than before? In the documentary, I found it fascinating that the bodies/minds of the naturally thin folks rebelled, in various ways, to the over-consumption of food (i.e., some had a gag reflex & just could not force themselves to eat more; another participant actually gained muscle despite having done no exercise and that extra muscle increased his metabolism to fight against weight gain; the scientist conjectured that two others fidgeted more to get rid of the extra energy).

I don't think it is primarily genetic. Food environment has a whole lot to do with it. Not to mention the physiological response to food (endocrine theory) compounds and accelerates each generation.

So if there is an interaction among genetics, industrial foodstuffs, and our body's increasing inability to tolerate the inflammation caused by some of these factors (note the increase in things like IBS and food allergies) - then all you need is to add in an improper response to hunger (like boredom eating and the easy availability of nutritionally poor food) and more sedentary behavior - somewhat abruptly we observe a significant portion of the population that previously would only be subject to a middle aged spread hitting record levels of obesity and corresponding ailments like diabetes, heart disease, high cholesterol, etc etc.

I support an endocrine theory for obesity, meaning that obesity and overeating are symptoms of a dysfunction in the body's energy processing and hormonal response to food input, not the root cause of it. But that doesn't preclude all the above factors also affecting the equation. And while solving it can be as simple for some people as just adopting more mindful eating habits and using an external check like calorie counting, for a fair portion of the population they must address the physiological problems as well as the behavioral and environmental interference.

Just want to say thank you for your post. You described my husband and I to a T. I've never heard it explained this way but that is exactly us!