Don't worry about calories or weight loss. Do what you enjoy. Ride your bike your way.
My optimal weight is 150. almost 20 years ago, after I was hit by a car, breaking my neck and back, I was unable to ride a bike and for the next 15 years needed a cane to walk. I got up to 205 lbs. And I developed Hashimoto's, an auto-immune disease that attacks the thyroid. So I had chronic pain associated with Hashimoto's, and no energy to exercise anyway.
To lose some weight I changed my diet. I quit buying ready-made sweets and treats. I bought the fixings to bake muffins, cakes, etc., if I wanted those. Yeah, I cheated occasionally but mostly stuck with that plan and it worked. I cut way back on the beer. I ate a lot more high protein/fat foods to satiate my hunger. If I didn't let my blood sugar drop, I didn't crave sugar and junk carbs. But I'm an omnivore. I doubt I could succeed with a vegan or vegetarian diet. Tried it for several months, hated it.
That got my weight down to 175 by early 2015. And I was able to walk farther without the cane. So in summer 2015 I bought a bike, a heavy comfort hybrid with spring fork, heavily padded and springy saddle, and rode that thing for a year. Slowly. No diet changes. I lost maybe 5 lbs, but felt better.
Each year since 2015 I've made other changes to my diet and exercise routine, and each year rewarded my efforts with a new-to-me used bike that's a little lighter and a little sportier. In summer 2017 I got my first road bike in 30+ years. Weighed about 160 lbs then.
In 2018 I was hit by a car, again, breaking my shoulder and re-injuring the old neck injury. Diagnostics to check the injuries revealed my thyroid was calcified. Biopsies confirmed it was cancerous. I had surgery in late 2018 to remove it. No metastasis, no chemo, I got lucky. So far, so good.
Most of 2019 was a slow recovery. Zero energy for months. Weight dropped to 150, mostly because I couldn't swallow solid food for months. Lots of protein shakes, blenderized fruits and veggies, oatmeal, soup, etc. Bought my first carbon fiber road bike from a friend. Early 1990s Trek 5900. I've been enjoying the heck out of that thing. It motivated me to keep going and regain the conditioning I'd lost to injury and illness.
By the time I felt better and could swallow again, I figured I might as well try to keep the weight within the 150-160 lb range. So far, so good.
Took awhile but I'm much stronger and fitter than I've been in years.
But if weight loss or fitness had been my primary goal, I'd have failed.
I ride bikes because I enjoy it. The brain chemical buzz is the best drug I've ever found, and I've tried almost all of 'em. I don't worry about my weight. I don't worry about calories burned during a ride. My main motivation to work out a little harder is so I don't get dropped on every hill in group rides. Other than that, it's all for fun. Sometimes working harder to get faster is also fun. But if it becomes a chore to work so hard at it that it ain't fun, I'll refocus on my primary goal: riding bikes to enjoy riding bikes.