Diet Talk

It was the evening of the day after Hayashi decided to go on a diet.

“Yamamoto, wanna go buy dinner?”

Hayashi invited me to head to the supermarket.

Come to think of it, I’d completely forgotten about our conversation yesterday, but I was supposed to help Hayashi with her diet.

“Sure.”

We left the room.

Our destination was the nearby supermarket… or rather, a supermarket about a kilometer away.

“Gotta walk, right?”

It was Hayashi who suggested going to the farther supermarket.

Upon closer inspection, she was wearing running gear she must’ve bought at some point.

You could tell how motivated she was about this diet.

“Just exercising vaguely won’t do much, you know.”

I immediately threw cold water on Hayashi’s enthusiasm.

“Huh? What’s wrong with that?”

“First off… do you even know how people gain weight?”

“How people gain weight?”

Hayashi looked at me suspiciously.

After mulling over my words for a bit, she glared at me.

“Isn’t it just lack of exercise or eating too much?”

“Why’re you glaring while saying that?”

Geez, Hayashi’s always so confrontational.

“Alright, let me ask you this: how much exercise makes it so you’re not ‘lacking,’ and how much food counts as ‘too much’?”

“I don’t know.”

“Heh.”

“Don’t give me that smug look.”

“Listen, the reason people gain weight is actually pretty simple… it all comes down to this: if your calorie intake exceeds your calorie expenditure, your weight goes up. Conversely, if your expenditure is higher than your intake, your weight absolutely won’t increase.”

That’s the conclusion I reached back in high school after researching while doing strength training.

…I’ve seen plenty of trainer videos that back up what I just said, so I’m pretty sure it’s not wrong.

“In other words, it’s not just about lack of exercise causing weight gain. Lack of exercise reduces calorie expenditure, which leads to weight gain. Same thing with overeating—it’s not the eating itself, but the fact that overeating increases calorie intake, which causes weight gain.”

“…So?”

“I’ll spell it out for you. You were planning to ramp up exercise and drastically cut down on food for this diet, weren’t you? Like, super extreme.”

“…Ugh.”

Looks like I hit the nail on the head.

“What I’m trying to say is, you don’t need to do anything that extreme. If you properly track your calories, you absolutely won’t gain weight. Like I said during the bookkeeping exam, vague plans don’t last. They make you push yourself too hard.”

“…Okay, so what should I do specifically?”

“First, you need to make a plan.”

As we passed the closer supermarket, our conversation continued.

“I mentioned calorie intake and expenditure earlier, but to lose one kilogram of fat, you need to burn about 7,500 calories more than you consume.”

“How do you know such specific numbers?”

“I looked into it a lot back in high school.”

I cleared my throat.

“So, to lose one kilogram of fat, you need to burn 7,500 calories more than you take in… after that, it’s just about setting goals. First, decide how much weight you want to lose and by when.”

“…Christmas is two months away, so I’d like to lose weight by then.”

“You… you said you gained this much weight, but I don’t think you need to lose that much, you know?”

Just as Hayashi was about to say how much weight she’d gained, she glared at me fiercely, so I gestured her weight gain with my fingers.

“Maybe half of that would be enough? Losing too much can be bad for your health, after all.”

“…Yeah.”

“Alright, so if you aim to lose five kilos in two months… that’s roughly one kilo every two weeks.”

“Got it.”

“That means 7,500 calories in two weeks. Roughly 500 calories a day.”

“…I see.”

“Yeah, and for reference, a 500-milliliter bottle of juice is about 200 to 300 calories. One rice ball is around 200 calories.”

“Wait, that’s it?”

“To get into the details, there’s stuff like metabolism, and you don’t drink juice every day, so it varies. But my point is, cutting 500 calories a day isn’t some impossible goal.”

“…True.”

Hayashi smiled, looking pleased.

“Professor Yamamoto! I’m actually getting pretty motivated now!”

“Who’re you calling that?”

It’s not exactly weird for me to feel flustered when someone who used to be called the queen is now calling me a professor.

“A-anyway… the point is, you don’t need to do some vague, extreme diet.”

Still a bit thrown off, I pulled myself together and continued.

“So, starting today, use a calorie-tracking app to keep tabs on your intake.”

“Can’t I just estimate it?”

“Using a calorie-tracking app lets you see numbers for the three major nutrients too. Skimping on nutrients just to cut calories isn’t good either.”

“Ohh… like how it makes you cranky?”

“Haha, your crankiness has nothing to do with nutrients, does it?”

She punched me in the shoulder.

It hurt.

“…Sorry.”

“Hmph!”

“…Oh, and starting today, you should use our body composition scale. That way, you can get a rough idea of your metabolism, which’ll make calculating calorie expenditure easier.”

“Got it.”

Alright.

With this, we’ve got Hayashi’s calorie intake and expenditure all mapped out.

Now…

“Now it’s about exercise.”

The release of the second volume of this work is just two days away.

I was thinking I’d keep posting daily until the release, but somehow we ended up with a diet discussion.

Wait, is this story a diet essay or what?