How I Lost 10 lb in 3 Months (and Exactly How You Can Do It Too)

I didn’t starve, I didn’t “detox,” and I didn’t guess. And I maintain for 2 years.

I used three things: a simple formula for rest calories, my watch’s active calories, and a food scale (just for a week to learn my portions). Then I chose macros that fit how I like to eat.

Use this as a plug-in guide in pounds, feet/inches. It’s written so any woman can do the math fast.

Step 1: Find Your Rest Calories (BMR)

Mifflin–St Jeor (women, in lb/in):

BMR = 4.536 × weight(lb) + 15.88 × height(in) − 5 × age − 161

Example (my stats for the “now” phase):
5′6″ (66 in), 119 lb, age 50
BMR ≈ 4.536×119 + 15.88×66 − 5×50 − 161
BMR ≈ 1,177 kcal/day

This is what your body burns at rest.

Step 2: Add Daily Movement

Two paths → pick one:

A) You have an Apple Watch/Fitbit (shows Active calories)

Your watch’s Active calories already include steps + workouts.
To estimate your full daily burn (maintenance), add digestion (TEF ≈ 10%) like this:

Maintenance calories ≈ (BMR + Active) ÷ 0.90

Example: BMR 1,177 + Active 500 = 1,677
Maintenance ≈ 1,677 ÷ 0.90 = ~1,863 kcal/day

The 500-Calorie Move Goal (My Non-Negotiable)

There’s no way around it: you have to move. I personally set a daily 500–600 active-calorie goal and treat it like brushing my teeth, non-negotiable. Pick movement you actually like and repeat it most days. My base is 10,000 steps (non-negotiable), which on my body is ~320 kcal (at ~120 lb using the steps formula). Then I top up with 20–30 minutes of swimming (surprisingly high burn for the time), or 30 minutes of weights/resistance (vital for muscle and shape), or yoga (great for mobility/stress, lighter calorie burn). The goal isn’t perfection, it’s accumulating movement you’ll stick to so your math works without misery.

B) No watch? Use steps (quick estimate)

A decent rule-of-thumb:

Active calories from steps ≈ steps × 0.04 × (your weight / 150)

• 5,000 steps at 120 lb → ~160 kcal
• 8,000 steps at 120 lb → ~255 kcal
• 10,000 steps at 120 lb → ~320 kcal

Then plug into the same formula:

Maintenance ≈ (BMR + Active-from-steps + extra exercise) ÷ 0.90

It’s an estimate. If your weight holds steady for 2+ weeks, you’re at maintenance. If it drifts, adjust ±100 kcal.

Step 3: Create a Gentle Fat-Loss Target

Once you know maintenance, set a 300–400 kcal/day deficit.

• My maintenance (with watch) ~1,860 kcal
• Fat-loss target = ~1,500–1,560 kcal/day

That’s it. No “1200 calories.” No misery.

The First 3 Weeks: Don’t Panic

When I started, nothing moved for almost three weeks! But then boom, the scale finally slid. Early on your body’s juggling water + glycogen, salt, new-fiber bloat, and exercise water retention, so real fat loss can be masked (hormone shifts don’t help). Don’t quit. Run the plan for a full month: hit your 500–600 active calories, keep protein high, weigh the calorie-dense five, and log honestly. If after ~4 weeks your weekly average hasn’t budged, reassess and trim ~100 kcal/day (or add a bit of movement). Tiny tweak, not a crash.

Step 4: Track Briefly (Irritating for a week, then easy)

• Weigh your food for 7–10 days. Use FatSecret, Lose It!, MyFitnessPal, any app.
• The goal isn’t perfection; it’s education. After a week, you’ll know your go-to portions.
• When you’ve reached your goal and held steady, you can shift to intuitive maintenance using the same foods/portions you learned.

Calorie-dense foods are sneaky. I recommend weighing them regularly because even 10–50 g over can add a lot of calories. Keep the scale out for oils, butter/ghee, salad dressings, nuts/nut butters, cheese, granola, avocado. Quick reality check: 10 g oil ≈ 90 kcal, a loose “handful” of nuts can jump 150–250 kcal. These are the places portions drift fastest, even when everything else looks perfect.

During fat-loss, I weigh most things so my deficit is real, not wishful thinking. Once I’m at maintenance, I relax: I eyeball lean proteins and veggies and only keep weighing the calorie-dense five (oils, nuts/nut butter, cheese, dressings, granola). That way I stay free most of the time without letting portions slowly creep up.

Apps I Actually Used (All Free Plans)
I tested a few free apps and any of them will work: FatSecret, Cronometer, MacrosFirst, CarbManager. My current favorite is CarbManager because carbs are the main category I watch to maintain. Its carb view makes it stupid-easy to see when I’ve crept up.

Why I Watch Carbs (My Experience)
For me, weight bumps show up fastest when carbs creep up. If I overdo fat or protein a bit, it doesn’t register as sharply on the scale but extra carbs often do. Partly because carbs are easy to “snack add,” and partly because higher carbs = more water held with glycogen, so the scale can jump. So at maintenance I keep fat around 0.45 g per lb body weight (for me at ~120 lb that’s ~54 g) for satiety/hormones, keep protein high, and set a simple daily carb cap that fits my calories.

Step 5: Pick Macros That Fit You (3 easy options)

First, set protein. It protects muscle, keeps you full.

• Protein (grams) = 0.8–1.0 × your weight (lb)
  (Use the 1.0 number while losing; 1.0–1.5 at maintenance.)

Then pick your fat style, and carbs are “the rest.”

• Higher-fat / Lower-carb: fat = 0.7–0.8 × weight (lb)
• Moderate-fat: fat = 0.4–0.5 × weight (lb)
• Lower-fat / Higher-carb: fat = 0.30–0.35 × weight (lb)

Carbs (grams) come from what’s left:

Carbs g = (Calories − (Protein g×4 + Fat g×9)) ÷ 4

Plug-in examples (for a 120-lb woman)

A) Fat-loss day (~1,500 kcal)

• Higher-fat / Lower-carb: 120P / 70F / ~98C
• Higher-protein / Moderate-fat: 150P / 45F / ~124C
• Higher-carb / Lower-fat: 120P / 35F / ~176C

B) Maintenance day (~1,800 kcal)

• Higher-fat / Lower-carb: 120P / 100F / ~105C
• Higher-protein / Moderate-fat: 150P / 60F / ~165C
• Higher-carb / Lower-fat: 120P / 40F / ~240C

My current preference at maintenance: higher protein, moderate fat, lower carbs mostly from veggies + high-fiber carbs. (Think: 130–150 g protein, ~50–65 g fat, carbs as needed.)

Step 6: Nudge Back to Maintenance (when you hit goal)

Maintenance Tracking Style (What I Actually Do Now)

I don’t log every day at maintenance. I eyeball most meals and only spot-check in CarbManager for 2–3 days when clothes feel snug or energy dips. My checklist: protein 130–150 g, fat ≈ 0.45 g/lb, and carbs mostly from veggies + high-fiber carbs. That keeps me steady without micromanaging.

• Add +100–150 kcal/day each week until weight holds steady.
• Keep protein strong; add calories where you like (a bit more carbs around workouts, or some extra fats if you prefer them).
• Watch biofeedback: energy, sleep, mood, cycle, recovery. If those dip, you might be under-fueling.

My Before/After (so you can see the math in action)

• Start: 5′6″, ~130 lb → BMR ~1,227
• Now: 5′6″, ~119 lb → BMR ~1,177
• Active (watch): ~500 kcal/day
• Maintenance (now): (1,177 + 500) ÷ 0.90 ≈ 1,860 kcal
• Fat-loss phase: I ate ~1,500–1,600 kcal, high protein.
• Time: ~3 months → ~10 lb lost, steady, livable.

What to actually eat (quick ideas you can copy)

• Protein anchors: Greek yogurt (0% fat to save on calories here), cottage cheese, eggs/egg whites, chicken/turkey, fish, beef, pork, lamb, tofu/tempeh, protein shakes.
• Fats you’ll feel: avocado, olive oil, nuts, seeds, sugar free cacao
• Carbs that behave: veggies, berries, beans/lentils, oats, quinoa, potatoes, whole-grain wraps, aim for fiber.

My Full-Stomach Trick (Volume Veggies)

I love the feeling of a full stomach, so if a meal is too light, I’m unhappy. My fix is obscene amounts of veggies: I’ll roast a full sheet pan of broccoli, Brussels sprouts, and green beans with salt + spices only (no oil) and eat the whole tray with a protein (chicken, fish, tofu, cottage cheese). Huge volume, very few calories, and I finish the meal actually satisfied instead of hunting snacks.

Tiny rules that helped:

• Build every meal around a protein + a produce.
• Pre-log dinner in your app, then fill the day around it.
• Salt, spices, and pickles save sanity.

FAQ (because someone will ask)

Do I have to weigh food forever?
No. Use the one-week boot camp to learn your portions. Keep it handy when you drift.

What if my scale/app says something different than your math?
Trust trends over any single day. If weight won’t budge after 2–3 weeks, adjust by ±100 kcal.

Is high protein safe?
For healthy kidneys, 1.0 g/lb is widely used in fitness & body-recomp. If you have medical conditions, ask your clinician.

Your 60-second Setup (fill this in)

1. Weight (lb): ____ Height (in): ____ Age: ____
2. BMR = 4.536×lb + 15.88×in − 5×age − 161 = ______
3. Active: watch ____ or steps → 0.04×steps×(lb/150) = ____ (+ any workout cals)
4. Maintenance = (BMR + Active) ÷ 0.90 = ______
5. Fat-loss target = Maintenance − 300–400 = ______
6. Protein (g) = 0.8–1.0 × lb = ______
7. Pick fat style (0.3–0.35 / 0.4–0.5 / 0.7–0.8 × lb) = ______ g
8. Carbs (g) = (Calories − (Protein×4 + Fat×9)) ÷ 4 = ______

Print that, fill it once, and you’re set.

Final nudge

You don’t need to be perfect. You just need a clear plan, a one-week track-and-learn, and a macro setup that fits how you like to eat. That’s how I lost 10 lb without losing my sanity and how you can, too.