If fructose raises triglycerides:
and triglycerides downregulate the passage of the main satiety hormone (leptin) across the blood-brain barrier:
and also upregulate the passage of the main hunger hormone (ghrelin) across the blood brain barrier:
and since triglycerides correlate to obesity:
...it seems to me that simply eating a lot of fructose while being sedentary would be enough to set the stage for most cases of obesity. So, what I'm looking for are exceptions to this. I know someone here mentioned that they had gotten obese without eating a lot of sugar, but they were taking corticosteroids if I recall, which greatly increase appetite. The tough thing about this is that fructose has completely pervaded processed food, so people could be consuming significant amounts without actually eating perceptibly "sweet" foods.
Nevertheless, I think it's safe to assume that the primary fructose delivery vessel is sweetened drinks of some sort and that it would require that kind of volume in order to actually increase triglycerides enough to make a difference. This is assuming that there is a concomitant lack of activity, since exercise decreases triglycerides:
Any input is appreciated.
I gained something like 60 pounds over a year eating a vegan diet of (essentially) cous-cous, brown rice, homemade bread, steamed veg, lots of soy, nuts, and "healthy" oils like olive and flax. I don't think I touched much fructose besides the occasional piece of fruit. I also lost weight initially on a fruitarian diet, but then re-gained the weight and then some when I increased my calories to the recommended level of 2500-3000 for women, when I was losing weight on fruitarian I was eating around 1000 calories of apples, melon, oranges, and grapes.
Based on that experience, I don't think you need fructose to see obesity. Also, my experience losing weight with paleo is that I can eat between 50-100 carbs of lactose and fruit and see steady loss, but replace those carbs with starch from potatoes and I see steady gains. It's not so cut and dry I think.
I was never a fruit eater, candy eater, or soda drinker, and yet steadily grew fatter since menarche at age 13. My go-to foods were pasta, bread, and breakfast cereal, including a deep love for cream of wheat and cream of rice. Even cookies, cake and ice cream were rare treats; it was the daily starches that I craved.
And although I longed to be sedentary, I forced myself to work out at least three times a week, often quite a bit more than that. It was clear to me early on that I had to work out very hard and very long to see even a two or three pound loss, although I did build up a great set of muscles under all that blubber. Being asthmatic and clumsy didn't help, I'm sure, lol.
Before I stumbled across LC at age 38 (yes, I'd been living under a diet rock, and thought all book diets were crap -- "If any of them worked, we'd all be doing that one," is how my thinking went), I periodically would go on a 500 cal/day diet, plus workouts, that I could sustain for maybe three months at a time, at the most. Each time I started and ended at a slightly higher weight than the prior time I did it. Sigh.
The first time I LC'd (and lost around forty pounds -- I thought I'd hit the diet jackpot!), I quit after four months or so when my doctor told me Atkins was "the worst diet in the world." After ballooning up even more to 220+ pounds (and being scared to death I'd end up at 300+ like my biological mother), I hired an expensive nutritionist to "supervise" me on a 1200-cal/day diet, composed almost entirely of whole grains, green vegetables, and nonfat yogurt, on which I technically gained weight (one pound, so I supposed that should just be marked down as "failure to lose").
Bottom line: I'm pretty sure it's possible to get fat without "excess" fructose; for some of us excess starch/carbohydrate in general seems to do it. I do wonder if you're on to something with the male/female distinction -- He Who Shall No Longer Be Named noted that in traditional societies that fatten, it seems to be the women who get hit first and hardest by obesity and diabetes.
I attribute my former obesity and D2 to overeating dry breakfast cereal. This was a mix of simple carbs from wheat starch, sucrose, lactose and glucose (raisins in raisin bran), but fructose was minimal. I was also very sedentary.
My dad consumes pounds and pounds of fruit daily, but very little fruit juice or soda and he is very lean at the age of 50. I am still a bit weary of fructose, but it seems if it is naturally packaged with all the micronutrients and fiber it has very little negative affects.
I think it's good evryone's looking at pausible causes for obesity (sugar,starch,grains etc.) Yet I feel one very important one is being left out....MSG. It is used in almost everything processed and sometimes even organic. It causes lots of neurological problems,but it's also a proven stimulant to keep on eating beyond satiety. I know it definitely has that effect on me!
When I first went vegetarian I was consuming no fructose--almost exclusively McDonald's french fries every day--this was after they had switched to using vegetable oil. Gained lots of weight.
I got fat on a whole foods home-made vegetarian diet, but it took me a number of years to do so. I got obese when I started eating meat and fructose in my 40's. (I had read about aspartame, and also about the good things of fructose lol) During my veggie years, my triglycerides were much higher than in the later years. My mother, otoh, was well into middle age before hfcs was invented. She is old enough to remember when it was commonplace for dieters to reduce their carbs. Though she was a fat child, and sometimes heavier into middle age, she did not like sweets. I don't recall ever seeing her eat dried fruit, chocolate, soda, candy, muffins, sugary cereals, etc. She did not bake or have pastries in the house. I only remember cheesecake and what we would sneak in for ourselves. She got fat on bread and potatoes. Not very much, though. Her one weakness was if there was a bag of potato chips around, she would finish them off. But she used to have them only for entertaining, maybe 3 or 4 bags a year. If she had any sugar at all, it was in the form of salad dressings, which she craved along with other vinegar tastes. I know lots of people here don't want to hear that people can get fat with potatoes and starches, but it is very true.
When I first transitioned to paleo, I ate a carton of strawberries every day for about a week. Stawberries are low in fructose but I surely dropped pounds of fat in those first true paleo weeks even with a moderate intake of fructose.
I ate nothing but 3-4 pounds of dates daily with some OJ for good measure(usually 1/2 gallon) for about 8 months and I lost weight down to the lowest I've ever been in my life at 140. I think it should be noted that about 1 year before this point I was ~50lbs overweight.
I think the weight gain with fructose probably has a lot to due with the fact that most people eat it in foods that literally have zero nutrition. It's also really easy to down a 32oz coke with a huge burger and fries.