Last year around February I made a decision to lose weight, I went through all the fad diets: Keto, Carnivore, and some other one I can't remember. None worked, so out of desperation I went to ChatGPT and I'll summarize what it said:

- Ignore reddit fitness fitness advice

- Avoid fitness influencers

- Stick to the science

- Don't do Keto or fad diets or crash diets, I'd likely lose around 20% of muscle.

Basically it recommended not to crash diet, or even diet at all but instead do a recomposition. So I lifted weights, walked 10-12k steps daily, and cut calories by only 200 to 300 a day, hit all my macros not just protein. After the initial weight loss my goal was to aim for -0.3 to -0.75lbs a week. Sometimes I went higher trying to dial in my calories. I now have noticeably more muscle and look lean.

I posted this on a fitness subreddit and people were very angry at me for using ChatGPT. I really don't get it, because it worked for me while their advice failed me. My blood work is better, I no longer have a huge gut, sleep better, it really was a life changing experience.

Also ChatGPT will give me sources for the scientific approach that I can read up on.

Just wanted to share this.

Edit: For people asking about the prompt. I looked through them and it isn't a single prompt but a series of interactions that lasted months where I was learning about calories, what macros are, the basic science of weight loss etc. Each prompt on it's own it's not useful but the knowledge I gained over the sum of months of interactions is what was valuable. I tried looking for the first interaction very briefly but this was made so long ago and I used chatGPT daily because of how effective it's been for my weight loss, I now use it for all sorts of things so it's burried under a mountain of other interactions. I watched fitness videos on youtube and copied the transcripts of the video into chatGPT to make sure this advice wasn't woo woo but was actually solid advice grounded in science. I still do this today to make sure I'm not distracted by click bait videos. I attached a prompt that might be useful.

https://preview.redd.it/xs1ziqhtw2tg1.jpg?width=2225&format=pjpg&auto=webp&s=a9e58fc45f3e6c56ad91ca74372baeb07e885b70

This is the playbook that ChatGPT mentioned at the bottom of this interaction copy and pasted:

💪 Simple Fat Loss Playbook (What Actually Works)

1. Calories matter most

You lose weight by eating fewer calories than you burn. Period.

• No diet (keto, paleo, etc.) overrides this
• You don’t need to cut carbs or do anything extreme
• Just aim for a small deficit (~300–500 calories/day)

2. Eat enough protein (this is HUGE)

Protein helps you keep muscle while losing fat

• Aim for ~0.7–1g per pound of body weight
• This keeps you fuller and helps your body look better as you lose weight

3. You don’t need to suffer

If it feels miserable, you’re doing it wrong

• You shouldn’t be starving all day
• You don’t need to eat 1,600 calories unless you’re tiny
• Sustainability > speed

4. Move more (but don’t go crazy)

Walking is underrated

• 8k–12k steps per day is plenty
• Lifting weights helps keep/build muscle
• You don’t need endless cardio

5. Ignore fad diets (like keto for most people)

They work because they reduce calories—not because they’re magic

• Keto can actually hurt gym performance for a lot of people
• If you can’t stick to it long-term, it’s useless

6. Expect fluctuations

The scale will mess with your head if you don’t understand this

• Water weight can hide fat loss for days
• Sleep, sodium, carbs, workouts all affect scale weight
• Look at weekly trends, not daily numbers

7. Consistency beats perfection

This is the real secret

• You don’t need perfect days
• You need repeatable days
• Small wins stacked over months = big results

🧠 The mindset shift (this is what changed everything)

“I stopped looking for the perfect diet and just focused on what I could stick to every day.”

🔥 If you want to give them a super short version:

“Eat a little less than you burn, hit your protein, walk a lot, lift if you can, and don’t overcomplicate it.”

If you want, I can tailor this into:

• a Reddit-style post
• a text message version
• or a beginner step-by-step plan for them specifically

Just tell me 👍