I accept the wisdom that once you're on a paleo-esque diet and off of superstimulus like sugar, food cravings are something to be taken seriously (I could really go for some thymus right now), but does anyone have a scientific or evidence based perspective on this?
I can vaguely recall a studio showing that when children are allowed to choose their own food from a limited set of non super-stimulating foods, they will eat a nutritionally complete diet. Can anyone dig up the study I'm thinking of or something similar?
No study, but a relevant anecdote...I was lucky enough to spend Christmas week this year in Hawaii, where my primary activity was soaking up all that magical magical sun. Literally an hour a day, every day for a week, no sunscreen, no nuthin. Miracle of miracles, unlike my previous 33 years of life, not even a hint of a sunburn, just a happy vitamin D factory. Unfortunately, also no real tan. I get home, and every single vegetable I crave for an entire week is orange- sweet potato, pumpkin, carrots...every single meal. And over the next four days I gain about five levels of color. One morning, I wake and am done with my passing orange obsession; must have gotten the vitamin A my body wanted to balance all that D.
I've had similar phases with grass fed butter, sardines, lamb...any healthy craving, just ride it out and trust that your body wants sane things for the current situation.
Specific food craving (a desire for a very specific type of food) is more likely your body's need for a nutrient or component of that food -- your body has come across it somewhere and your subconscious makes the link (but not always accurately). Most common examples are the cravings (and aversions!) that occur during pregnancy.
General food cravings (a desire for food above and beyond what's necessary) can be tied to our genetic heritage. As Michael Pollan points out, our ancestors lived in a feast/famine situation, when food was available, we grabbed as much as possible (ensuring our survival through lean years). This also explains our fat and sugar addictions, easily and cheaply stored by our bodies, providing a readily accessible source of energy later on. In modern society, when food is always available, that feast reflex isn't doing us a whole lot of good :p
From Peter at Hyperlipid:
"One day I found this paper on diabetic rats. I'm not really sure how similar streptozotocin induced diabetes in lab rats is to type 2 diabetes in humans. Insulin production is blunted but not eliminated, so perhaps it is the equivalent to fairly late type 2, when the pancreas has finally started to give up under the strain of the ADA carbohydrate based diet. The paper was quite interesting from the point of view of hunger.
"Lab rats don't generally get described as being lazy glutttons. Sitting in a cage all day limits your trips to the gym. You eat what the investigator gives you. It seems quite reasonable that rats eat to satiety and no more. Beyond that would be gluttony. But if you make a rat diabetic, then feed it a carbohydrate based diet, it exhibits "hyperphagia". It eats a LOT. And it becomes fat. Perhaps a little bit of streptozotocin and some lab chow equals gluttony.
"Obviously no self respecting rat wants to be either diabetic or hyperphagic. Luckily rats are not stupid and, given a choice of macronutrients after its streptozotocin, a lab rat will automatically dump the carbs, eat the fat and keep both its waistline slim and its blood glucose within acceptable limits."