Even on keto (for weight loss purposes) you don't need to add extra fat either. You just eat naturally high fat foods and cook with healthy fat. Adding extra fat comes in later when you want to slow or stop weight loss.
So it's ok to put butter on veggies and cheese, mayo and sour cream on whatever you like, but you still have to manage portions and energy intake. The same would be true on the high carb diet.
Keto isn't eating high fat. It's eating very low carb. That's why you can't really go keto in baby steps. You can cut carbs in baby steps... but it's not keto until they're very low and maintained.
And you cannot do a keto day here and there because you won't be able to achieve ketosis that way. It requires consistency.
However, you don't have to be keto to lose weight. Lots of people here do great with low carbs up to 100-150g a day. It still comes down to what those carbs come from though. You can't do low carb where you eat no carbs all day long so you can use them all on a bowl of ice cream at night. You don't want to have a large sugar influx like that at one time. You'd want to get your carbs from vegetables, possibly even starchy ones if that's your choice and some low carbers even include small amounts of whole grains if it works within their goals. They aren't using their carbs for junk foods in other words. That's not the path to long term behavioral changes.

My honest opinion is if you hold onto the idea that getting rid of that food is wasteful so you must eat it, you'll have trouble any time in the future you're given something that doesn't fit your plan for the same reason. It's waaaaay to easy to justify eating something that you've previously decided you shouldn't. I'd say losing weight is 98% a mental game and this idea of wastefulness is an incredibly common theme.

We are here for support whatever version of low carb you find yourself fitting into though. Best of luck to you! You can do this!

I'm in the camp of "can't throw things out". I currently don't strive for ketosis but rather I still eat what the general public would consider (possibly ) very low carb. I ate a banana the other day (happened to be 4 ounces, weighed it). Not the best choice for low carb (I'm not diabetic etc) but nevertheless my total carbs for the day 52 (22 from the banana) and net was 45 (if that matters). The banana was more ripe than my husband would eat and I couldn't bring myself to pitch it, so I ate it. I have been known to run an 85% cocoa bar down the garbage disposal.I tried them. I noted how I reacted to them behaviorally Over ate). I got rid of them and never bought one again.

This would be my guideline: if it is not something I am going to over eat and can therefore stay within my allotted calories and general macro amounts, I'll eat it. I ate strict keto for a year which limited both carbs and protein in that it was a medically therapeutic version of keto. Back then, I would not have eaten the banana.

Many people (dare I say most) do not need to be in ketosis to lose weight. Why are you striving for ketosis? The best keto will do for the masses of people who became overweight because they over ate, will help minimize hunger and reduce cravings-my opinion that some will concur with. In that (reduction of hunger/cravings) occurring with me on keto, I was given the ability/freedom to then focus on my eating behavior/s. Behaviors (over eating, choosing the wrong foods/right foods to cause satiation, eating when not hungry, eating too fast).

To answer your question: high carb/moderate fat is can be ok for weight loss if what you are eating does not cause you to overeat your calorie need for weight loss. If you're going to "pig out" on whatever is in the pantry, you might want to toss it down the disposal but that is up to you. I lost my weight just fine eating starchy/carby legumes but not eating potato chips and ice cream. That fat/sugar/carb combo is detrimental to me because I'll over eat it nearly every time.

Ask yourself the real reason for not throwing something away and be honest. It well could be because you are frugal.

I would probably work with a moderate carb lower fat diet until you clear the pantry. I think it generally messes with electrolyte levels to jump in and out of ketosis every day or two and will probably leave you feeling not so great.

I gave a lot of food away to a 'soup kitchen' run for the homeless. It was mostly dried food, still in their original packaging, and maybe a couple had gone beyond the 'best before' date, by perhaps only a month, two at the very most....
To my irritation, the at the kitchen cook threw those away, but as a Cook myself, and trained in UK Food Hygiene Standards, via a Government Agency, I know, for an absolute, undeniable fact that there was absolutely nothing wrong with those foods and using them would have posed no problem at all, to anyone.

Still.
It was their decision, not mine. All I know, is that the food wasn't wasted by me. And to be fair, they used everything else...

I did, however, fill a small pedal-bin-liner with white flour (self-raising AND plain) wholemeal flour, pasta, old breadcrumbs and old rice. Most of these products were opened, and had honestly been in the containers for more than 6 months. One container I know for a fact, had flour in it that must easily have been 2 years old. At least.
So disposing of that lot had no effect on my pocket, directly.
It cleared out an awful lot of kitchen space though!

So yes - while I totally get your angle on not wasting food, @feathernaut , there are other things you can do with it, that will benefit others, or will (more importantly) safeguard your health.
Don't look at it as being wasteful. I know you have regrets (I did, chucking all that opened stuff in the bin!)

But - that's the whole point of LCHF. You NEED to get rid of it.

What you're doing essentially, is saying "I know the ship is sinking, but while I use a kid's bucket to bail the water out, I'll just open all the portholes to let more water in...."
It hurts. I know it hurts. I get it.
But - get rid of it. Give the kitchen a good clean, rejoice in the extra space you gain, give to others (I gave all my frozen bread, frozen ready-rolled dough, frozen wraps and frozen baguettes to my neighbours - they were thrilled!) and you'll be on the straight and narrow to 'proper' LCHF!

I changed my diet not my husband's diet. He's thin, healthy and active. He likes gravy on his mashed potatoes so I have flour in the fridge. He likes his tacos in a shell so I have a bag of Maseca in the fridge. He occasionally enjoys a piece of deep fried fish so I have cornmeal in the fridge. There's even a bag of sugar in the pantry that gets used every now and then such as a tablespoon in a huge bowl of coleslaw that I might make to take to a bbq or even make a small batch for home.

Speaking of sugar, I'll occasionally bake something for a party or holiday. I don't bake keto or low carb stuff because I am the only person I know that eats "this way" exclusively. Point: confectioners sugar. I try to buy only what I need for my baking event and if there is any leftover it will go in the trash. I might be "ok" with it around these days but I'm not willing to test my willpower of not making a bowl of butter cream frosting to eat by the spoonful.

So I guess what I said in the 1st post applies. If I'm not going to overeat it, I don't worry about it being around. To tie all this into high carb/medium fat, there is a whole world out there that eats this way (hc/mf) and all of them will not become sick or diseased. Who am I to say they and all the literature/research that supports that way of eating...is wrong. It's not right for me.