I asked ChatGPT and Gemini how to lose 10kg in 90 days. The AI gave me a ‘brutal’ blueprint

Over the last year or so, I’ve been on a health journey of my own and have lost close to 15 kilos while feeling lighter, quicker and significantly fitter. During that process, I relied heavily on both ChatGPT and Gemini for everything from calculating meal macros and preparing diet charts to tracking workouts and fine-tuning my training routine.

That eventually got me thinking: what if I had to do it all over again? What if the goal was even more aggressive: losing 10kg in just 90 days? Is that actually possible?

To find out, I asked both ChatGPT and Gemini the same question: how would they help a vegetarian Indian male like me lose 10kg in three months while still preserving muscle and training regularly?

The answers were surprisingly detailed and brutally honest.

But before we get into all that, here’s the exact prompt I used for both chatbots. You can and should tweak this prompt based on your own diet preferences, body weight, location and lifestyle constraints.

Prompt:

I want you to design a hyper-targeted, 3-month grocery blueprint to help me lose 10kg safely but aggressively through a sustainable calorie deficit.

To make this completely accurate to my real-world life, you must strictly follow these constraints:

– Diet: Strict Vegetarian (No meat, no fish. Dairy is perfectly fine).

– Goal: High-protein retention while losing fat.

– I live in Delhi-NCR, India. Do NOT suggest Western health-fad ingredients like kale, avocados, quinoa, or berries.

– Every single item on the grocery list must be easily sourced from local vegetable markets or instant delivery apps (Blinkit, Zepto, Instamart) in India.

– Be clinical, realistic, and blunt. If my weight-to-timeframe goal requires intense discipline, tell me upfront.

– Break your response into two distinct parts:

– Part 1: The Core Strategy (My daily target calories, macronutrient split, and the logic behind it).

– Part 2: The Exact Weekly Grocery List (Categorized by Vegetables/Greens, Protein-Dense Dairy/Legumes, Grains, and Essentials, complete with approximate local quantities needed for one person).

– Part 3: What to Cut (The specific, everyday sneaky elements I must eliminate from an Indian kitchen immediately to hit this goal).

Give me the raw, unvarnished blueprint. Do not use generic motivational fluff.

What ChatGPT said?

Right at the start, ChatGPT warned me that this aggressive target of losing 10kg would not be “comfortable”.

“You are aiming to lose roughly 0.75kg per week. That means a sustained calorie deficit with very little room for cheat meals, random snacking, or weekend overeating,” ChatGPT said.

The chatbot estimated that someone weighing 65kg and regularly going to the gym would have a maintenance calorie requirement of around 2,200 to 2,500 calories per day. In order to lose 10kg in 90 days, it suggested staying within a range of 1,600-1,800 calories per day.

To survive this deficit, ChatGPT told me to lean heavily towards protein-dense foods like paneer, hung curd, Greek yoghurt, tofu, soya chunks, whey protein, milk, moong chilla and legumes in controlled portions. The chatbot also said that I could still have rotis and rice in my diet, but they should support meals, not dominate them.

ChatGPT also warned me about the hidden calories that most Indian households add through tadkas and cooking oil, estimating that they can quietly add another 300-500 calories a day.

The chatbot then went on to create a weekly grocery blueprint for me, detailing the exact quantities of vegetables, fruits, dairy products and protein sources that would help maintain satiety while staying in a calorie deficit.

What Gemini said?

Gemini also used its memory to remind me about my heavy strength-training sessions and other physical challenges I have planned this year.

The chatbot warned me: “Your margin for error is zero. You will be hungry, and your training recovery will be heavily taxed.” It also said that trying to lose nearly 15% of body weight in such a short period could lead to muscle loss, recovery issues and nervous system fatigue if not managed carefully.

Subsequently, Gemini asked me to stay within a 1,500-1,600 calorie diet if I wanted to lose 10kg in the next 90 days. According to the chatbot, the diet should contain around 140-150g of protein, 120-130g of carbohydrates and 45-50g of fat.

The AI assistant urged me to rely on foods like high-protein paneer, soya chunks, moong sprouts, dalia, whey protein and besan chillas for protein, while recommending spinach, bottle gourd, cucumbers, tomatoes, onions and cauliflower as low-calorie but highly filling foods.

Gemini also warned me about the hidden oil in Indian diets, along with sugar hidden in everyday food items, including sweetened yoghurt and jaggery.

“Zero is the only acceptable amount for this cut,” Gemini said.