[epistemic status: n=1, but the theory seems fine.  Mixture of theory and personal narrative.  Trigger warnings:  body image issues, money, and info-dumping without a great narrative flow.  I am not a good rationalist yet, haven't even finished reading the sequences yet, and this is my first long post on here.]

The obesity epidemic emerges from processed food manufacturers competing to get you to eat more of their product by any means necessary.  They try to make their product be digested as quickly as possible so you will be hungry again sooner (largely by pulverizing biomass before forming it into products).  They add salt/sugar/fat to make their product so delicious that it is literally addictive.  Both of these make you eat more of the product and enrich the food manufacturer, with a side effect of making you fat.

After years of failed attempts at calorie restriction without categorically changing which foods I eat, my solution was to boycott all these manufacturers completely.

As of six weeks ago, and continuing indefinitely, I only eat intact solid biomass, and I only stock my kitchen with what I am allowed to eat.  I do not eat any liquids, particles <5mm, or derivatives thereof.  The emphasis is on a wide variety of fruits, vegetables, and meats.  The intactness of the fibrous cellular matrix of the plant requires me to chew more and slows digestion.  Slowing digestion has two benefits: staying full longer, and preventing insulin spikes which cause leptin-resistance in the brain which makes you hungrier.  Leptin is the hormone that your fat cells make to tell the brain that you're fat so you should reduce appetite and increase energy expenditure.  Leptin is a really good hormone to have if you're trying to lose weight.  High insulin blocks the brain's ability to see leptin.

I can't stress enough how important the intactness of plants is.  If the carbs are located inside intact cellulosic cell walls, which are clustered together as an entire intact tissue of cell walls, it takes longer for the enzymes and bacteria in your gut to penetrate those cell walls and liberate the carbs.  This keeps insulin low, which makes the brain more sensitive to leptin.  Intactness also forces you to slow down and chew more, which allows time for other lagging signals of satiety to reach your brain.   If you've done much chemistry lab, you've seen that the smaller the particle size, the faster a substance can dissolve, ceteris paribus, because smaller particles have more surface area per unit volume.  I don't know of any other diets that explicitly prescribe larger particle size, but it seems very important.

Cooking can weaken or rupture cell walls, reduce the amount of chewing required, and accelerate digestion in general.  I still cook half my plants, but if necessary I will eat more raw vegetables when I want to run a deeper caloric deficit.  I avoid eating mush that has >8g carbs per gram of fiber (e.g., bananas, white rice, white potatoes).  This seems like a better rule than the arbitrary chronological cutoff that paleo uses to ban grains and legumes.  I allow grains and legumes iff they follow the above rule.  Quinoa, lentils, and nuts are fine but they're not a large part of my diet.

Another difference from paleo is that I drink unsweetened kefir as an unprincipled exception to the above rules.  It seems to cause a better ratio of satiety:calories than any other beverage, for reasons that are not well understood by me.  To facilitate long term compliance I also allow myself one whole wheat hamburger bun per day and a trivial number of calories from condiments/spices that break the first rule.

In spite of all the flaws in the evolutionary just so story about paleo, it seems to perform well for weight loss in empirical tests.  This diet I invented is sorta like paleo except I have a better rationale for which plants to exclude, based on a different story of how the fiber of an intact cellular matrix slows down digestion and enhances satiety signaling.   Negative studies of fiber were just using supplemental fiber isolate, which makes them irrelevant to my proposed mechanism.  The only appropriate tests in the literature so far are RCTs of diets that eat lots of intact plants and avoid processed food, e.g. Paleo and Mediterranean.  These studies are very positive.

Eating out is easier than expected, since most sit-down restaurants will let me order off-menu from ingredients they have on hand, and they always have fruits/vegetables/meats.  One can order a fruit bowl and an a la carte chicken breast for example.

Vegetables may be better for me than fruits due to avoiding fructose, but I don't really worry about eating a pound of mixed fruit every day.  Actually the way I got started with this was reading Walter Isaacson's biography about Steve Jobs, and his obsession with fruit.  I started buying ~9oz containers of fresh prepped mixed fruit and eating that for breakfast instead of cereal, and I noticed a huge improvement in my mood and energy levels.  Fruit is on the menu for 1-2 meals every day.  It may be less convenient for someone without the budget to spend $20/day on produce -- they'd have to do a lot of prep work or sacrifice variety.  Compliance has been way easier than I thought it would be, partly because I'm paying for convenience.   For motivation to comply, seeing the way girls swoon over Paxton Hall-Yoshida in the first two episodes of Never Have I Ever gave me a burning desire to do whatever it takes to get a six-pack.  Paxton has a hot body and not much else but a confident personality that derives largely from the way people treat him because of his hot body.

On the role of willpower, I envision the exercise of willpower as choosing a a point within a bell curve of possibilities of what similarly situated people would do in my shoes.  The farther from the center of the bell curve, the greater the effort required.  The location of the bell curve is determined by your environment, endocrinology, fitness, and genetics.  I can't rely on having enough willpower to consistently select a z>2 outcome,  so I try to shape my external environment and endocrine environment so that I don't need to rely overmuch on willpower.  A very important part of this is to only stock my kitchen with the allowed foods, and to have a definite plan of what I can order before I eat out.  But I still use a nonzero amount of willpower to limit intake.  One phrase that really stuck with me from "Gut Reactions" by Simon Quellen Field [trigger warning: fat-shaming and nitty gritty details of biochemistry/endocrinology] was that if you find yourself passing over some foods and searching for tastier foods, then you're not really hungry, you're just addicted to the taste.  I force myself to eat a lot of vegetables even though they're not the most delicious thing in my kitchen (although garlic salt makes them ok).  It's enough of a habit now that it doesn't require much effort.

For exercise, I have two Beeminder goals.  The strength goal is Pushups+Rows+Situps+2xPullups+2xDips > 75/day.   The cardio goal is floors of stairs + 50x horizontal miles on foot + 16.66x horizontal miles on bike> 85/day.  Any elevation gain is equated to floors of stairs.  Both of these feel pretty easy and unambitious since I have a home gym 6 feet from my computer, but they're enough to see a very significant impact.   For weight loss, I have a bodyfat% goal with a graph-editor step function that drops ~2% on the 15th of every month until I reach 10%.  I measure bodyfat% with bodpod on the 14th of every month.

This setup has worked extremely well for me.  In fact it's working so well that I bet my local rationalist friends $1000 for charity that I could get my bf% down from 20% on Feb 14 to 10% on July 14.  On July 14 I will publish whether or not I won the bet.  Long term I aim to stay at 10-12% indefinitely and stay on this diet indefinitely to optimize my SMV and health.