Sugar and carb cravings are common, and the occasional interest in a great dessert or pastry is definitely normal, but when it's a real craving: persistent and something that makes a person act at odds with their actual interests and health, then that's a sign that something's wrong.
There can be deep emotional and other physical causes of craving sweets and starches, but I want to focus on something more basic and very common: magnesium and chromium deficiencies.
A little physiology for understanding this issue:
We have sugar in our blood because all of our cells are fed by it (biohack folks: ketone discussion for another time). The body uses hormones (which are just chemicals that are interpreted by the body as signals to do or not do different things) to communicate whether the cells are being well fed and therefore whether there should be more or less sugar and insulin in the blood.
Insulin is a hormone that establishes the physical route for moving sugar out of the bloodstream and into cells where it can be used. To do that, insulin has to physically bind to the outside of cells, and it needs a few things to do that: the minerals, chromium and magnesium. If a person is deficient in either one (and deficiencies in both are common; the reasons discussed below), then the insulin won't work well, the blood sugar will be abnormally elevated a lot of the time, even while the cells are starving, and because the cells are starving, they will be sending out chemical messages that they are starving and that you NEED to give them the most easily accessible form of sugar you can: basic, simple sugar!
The bummer is that this creates a terrible cycle. You were already deficient in chromium, magnesium, or both, or this problem wouldn't have happened, but since you're now craving sugar and therefore probably eating at least a little of it, every time you do, your body tries to rise to the occasion and will grab and use up any bit of magnesium and chromium that it can in a desperate attempt to both meet your starving cells' needs and drop the blood sugar to a safe level. But even that was probably not enough, because your reservoirs of these minerals were already depleted, so now you're in a deeper hole, craving sugar at least as much as you did before.
Let's bookmark that for a second. Blood sugar is not the only thing that your body needs these minerals for. You use magnesium and chromium for a ton of different things. All of those systems are now suffering because your cells starving takes priority over most other processes and if at all possible, blood sugar regulation will steal them away from other needs. So these are some of the symptoms that can arise from this problem: muscle pain, aches, and twitching (because muscles are the natural reservoir of magnesium, and a deficiency will affect the muscles profoundly), low energy and easy fatigue (because magnesium is needed to produce ATP—our body's chemical form of energy), hormonal problems including menstrual issues, emotional instability/anger/anxiety/depression (because magnesium is a key part of producing all the varied hormones that you need), insomnia (because your body sleeps in response to hormones going up and down throughout the day, which, again, you need magnesium to produce), ineffective detox with a back up of toxins and all the symptoms that leads to: brain fog, migraines, offensive body odor, skin problems, etc., and many, many others. The list would require it's own very long blog post.
So why are these deficiencies so common in the first place? For one: it could be simply eating too much sugar. We could imagine a scenario we create where we start out with a good healthy baseline having a lot of magnesium and chromium, and that we are repleting those nutrients on a daily basis with a healthy diet, but honestly, eating the high amounts of sugar (even one soda per day, for example) that is considered normal in industrialized Western cultures like the US, is too much for our systems to keep up with without additional specific supplementation to manage this. (That's because when we were going through evolution, concentrated sugar was really rare and for most parts of the world, mostly only available seasonally, in the form of fruit. Fruit and other sugar containing foods also have things in them that make them different and less of a drain on the system than processed sugar, like vitamins, minerals, and fiber, which is gone into below.)
And that scenario is even dreaming that our diets are good enough to replete those minerals and nutrients that we need. It is very rare to come across someone whose diet will actually do that, and this is why: depletion of the soil and overprocessed food.
Depletion of the soil:
There are two ways to sustain farming soil's ability to grow plants. One way grows healthy plants with good nutrient profiles and the other grows plants that are basically functional, they have leaves, roots, fruit, etc., but they are nutritionally weak and prone to disease (JUST LIKE the humans that rely on these and on the cattle, etc. that are fed them, as a food source).
That first way is done by using traditional farming practices that our ancestors discovered to be sustainable and health promoting: rotation farming (putting different plants in a given plot of land each year, because different kinds of plants use up and put back different nutrients in the soil, and this fact can be used intelligently to actually make soil healthier and more nutrient rich even while using it. Rotation farming also includes periodic rest years, where the land grows nothing other than what will grow there all by itself - a break sounds nice, doesn't it? It works. Maybe periodic rest is something required even for our own health.) and heavy use of healthy and varied compost (fully rotted plant matter, taken just from the farm's otherwise unused waste products. This is in imitation of the forest and other natural environments, which can clearly sustain long term healthy growth and ecosystems, because they do fine if we leave them alone. Plants go through big annual cycles of seasonal death, which feed next year's growth). When we do it this way, we get plants full of varied nutrients: all the things they need to be their most varied, adaptable, and best selves, which equates when we eat them for us to be our most varied, adaptable, and best selves.
The other route to farming is the monoculture cropping prevalent in the US. This form of farming grows the same crop (sometimes a rotation, but not with the variation or timing needed for true plant vitality) year after year on the same soil, heavily depleting the soil of what the plants need to be vital. This fact is counteracted by the application of chemical NPK style fertilizer (nitrogen, phosphorus, potassium; note that magnesium, which should be prevalent in all plant matter, is not listed), wherein those specific nutrients may be repleted, and a few others, depending on the fertilizer used, but generally speaking, those nutrients were discovered to be the minimum requirement to maintain growth and those tend to be all that are applied. Nevermind the varied functions in both plants and us that need the wide swath of other possible nutrients. One of these is basic immune function. The plants are not getting what they need to function properly, so they are more susceptible to infection and the mainstream monoculture answer to that is not to supply the nutrient needed so that the plant can correct itself, but to apply some killing chemical: a fungicide, an antibacterial of sorts, a pesticide, etc. The conventional medical paradigm does the same with us: the question for them is not: why is this patient susceptible to this infectious disease, it's simply, "How can this infection be killed?", a route which we can see clearly will only yield another infection in the future because the weakness that allowed the infection to take hold in the first place has not been addressed.
As an example, sugar cane has a lot of chromium in it. Processed sugar has none. The other heavily processed routes that we've developed to meet our sweet tooth also have none: corn syrup, beet sugar, etc. Nature set up an interesting scenario for us. The possible reality is, before industrialization: if we want to eat sugar cane's sugar, we have to eat the sugar cane, and in doing so, we also get a dose of the mineral needed to effectively consume and utilize the sugar. (It's a similar story for other sugar sources: honey, maple syrup, etc.) But since we have taken the sugar cane and processed it, removing all the minerals from it and making it a pleasant sparkling white, we've managed to it something that causes imbalance. This is Frankenstein's monster—creating something that turns around and hurts us, not through any innate fault of its own but because we ignorantly created something harmful. It's fine and necessary to experiment and then realize we've done wrong (this is the nature of life: exploring and trying out what does and doesn't work), but when we realize something hasn't gone well, we need to correct ourselves. In this case, processed sugar (whether it be sugar or corn syrup) needs to be used only very sparingly, not something tossed into almost all processed foods and consumed at every meal
Ideally, of course, we reduce sugar intake to levels that are sensible given our evolutionary biology and we fix our farming/food systems so that we are eating real food (not heavily processed and altered; as Michael Pollan says: if you can't pronounce the ingredients on the package and/or your grandmother wouldn't recognize the ingredients as food, then don't eat it) that was grown in a way that promotes health for the plants, the farmland, and ourselves. We do this partly by "voting with our dollar". Promote healthy farming practices by buying from local organic farmers and ranchers. Support local co-ops, farmer's markets and non-local resources (Thrive Market, for example) that make these things accessible.
Realistically, even while doing the things mentioned above, because that's not yet the culture most of us live in, it can be an uphill battle to make your diet good enough to both supply what you need on a daily basis and to bring your reservoirs up to healthy levels so that you can tolerate periodic excesses like those that happen over the holidays. Because of that, it's not a bad idea to do some chromium and magnesium supplementation in a way that matches your individual needs. Usually, sugar cravings are noticeably reduced within a day and removed within a week. In a few cases, more advanced blood sugar issues like some cases of diabetes respond incredibly well to this supplementation. These facts are in direct contradiction to all those articles that come out periodically with the absurdly broad statement of: "supplementation has no positive effect on the body." There are so many different types of supplements, with different qualities of brands and forms, and rationales (or lack of), that that kind of blanket statement really doesn't make sense.
I am being intentionally vague about some details (dosing, forms of these minerals, etc.) because of the following: sometimes this (usually requiring some other aspects of treatment, but not always) works SO WELL and so quickly, that it can drop a medicated person's elevated blood sugar through the floor and then their blood sugar-lowering medication becomes dangerous. Lesser concerns, but still real issues are: magnesium and calcium block the body from absorbing the other one, so if you take either one too much or for too long, you'll become deficient in the other, and both of those are unhealthy scenarios. Like other high dosing of single nutrients in a specific manner for a specific result (increasingly true with the severity of your illness), you should have an appropriately trained healthcare practitioner guiding and following you to make sure you are staying safe.
The material above is not meant to be taken as medical advice, nor is the information here nearly complete enough by itself to make accurate or wise treatment decisions. Please talk with an appropriately trained healthcare provider before doing specific nutrient repletion.