What about with sugar from fruits? And the keto diet even says avoid bananas, which is like a top 3 fruit to me along with oranges and grapefruits.
The way I currently see things goes like this:
1. The bottom line for weight loss/gain/maintenance is CICO...calories in vs. calories out. You figure out what your body needs to calories for the day & then either reduce, meet, or exceed it, depending on which of those 3 is your goal.
2. To get in the best shape (by actually giving your body the macros it needs), you break down the calories into the 3 macros (protein, carbs, fats). That's the IIFYM calculator mentioned above.
3. Pretty much all diets work because they restrict you to eating fewer calories than you burn in some way. Some do it in more interesting ways than others. Intermittent fasting says you can only eat within a certain time window...well, it's hard to binge more calories than you need within the space of a few hours every single day. Keto is all protein & fat, which makes you feel pretty full, which kind of prevents you from over-eating. Paleo & Whole30 are the same way...when you're eating whole, natural foods, those tend to fill you up a lot more. A piece of chicken breast & a baked potato is pretty heavy in the stomach compared to say a smashburger on a fluffy bun & a Twinkie or two. To your body, in terms of weight loss/gain/sameness, what matters is the total number of calories per day, over time. Look at anorexic people...they're not skinny because they're eating the right foods or exercising, they're just heavily calorie-restricting.
4. I think being overweight is one of the worst things you can do to yourself. There are so many downstream risks from being too fat...Type 2 diabetes, high blood pressure, heart disease, sleep apnea, etc. Did you know that heart disease is pretty much entirely reversible? Entirely through diet, no less. Same for Type 2 diabetes...it's largely reversible & manageable through dietary intervention. Keep your carbs to under 75 grams per day for three days & see what your results are. The single biggest factor for coronary artery disease is insulin resistance, which is responsible for 42% of heart attacks. So I do like the idea of keto because it forces you to either zero out or follow a low-carb diet, and keeping your carbs in line, if you have insulin & sugar issues, is pretty important:
https://www.youtube.com/watch?v=da1vvigy5tQ
With that said, the more I've studied nutrition, the more I am a fan of being an omnivore & not restricting yourself to certain kinds of food if you don't have to (i.e. other than diabetes, food allergies, religious reequirements, etc.). For example, going vegan means having to properly manage your B-12 intake, and even that has some special requirements:
http://www.doctoryourself.com/nasal.html
With keto & possibly cutting fruit out of your diet, you're missing out on a lot of stuff like phytonutrients & whatnot. That's not to say it's a bad or an impossible thing...I went through a period of my life where I had a very restrictive diet because I was allergic to so many things, and I survived just fine...but I like the idea of balance in a diet, if possible, so having all kinds of good stuff like meat, vegetables, fruits, grains, seeds, nuts, greens, honey, and so on gives you a lot of exposure to different vitamins & minerals and stuff like that. Which is why I like macros for results...eat what you want, but with a focus on powering your body by giving it your body's personal requirements for protein, carbs, and fats. It's not the
only way out there, but it is pretty easy to do once you get the hang of it, which is one of the reasons I like it. I'd imagine something like a whole-foods-based low-fodmap macro-tracked diet is probably the best you can do for your body, but cupcakes are awesome & you're going to die at some point anyway, so I don't really see the point of not letting yourself enjoy food responsibly during your time on earth.
One of the things to keep in mind with diets are that diets are inherently, and by design, short-term projects. Which means that you get results in short order, but they don't stick long-term because it is a short-term project and not a lifestyle change. There are a lot of ways to do lifestyle changes by changing your habits, but going back to IIFYM, one of the reasons I like macros is that you're not having to constantly babysit yourself like a lot of people do who try to "have healthy eating habits". I have friends who are skinny through eating whole-foods-based diets & kind of associate stuff like big meals or junk food as "bad", and so certain food or food situations get negative connotations like "oh, I shouldn't eat that" & stuff like that, which I don't really like all that much. I'd rather just track my intake & eat what I want than constantly have that internal dialogue of "no" following me around. I mean, that's not the case for
everyone who has good eating habits, but I'm kind of an all-or-nothing person, so it's just easier for me personally to stick with a procedure I can follow in order to be successful at it.