I've been "dieting" without a real diet plan. Maybe you guys can make some suggestions

The stats: 5'8" started at 203lbs in December. For activity I used to regularly walk 9-18 holes of golf several times a week but since I stopped golfing last year because of my knee I really ballooned in weight. No set workout routine. I have gotten back into mountain biking and bike a couple of times a week usually for 1-2 hours as I build my cardio and body back up to cycling shape. I've always been in the 185 range through my 30's and 40's. My first target was to get back to 185 then hopefully even less. Turning 45 next month.

Dad bod at 43@185



I've always had horrible eating habits and have always ate whatever I wanted and however much I wanted. First thing I decided to do which I started in late December was to try to start eating better. I have no real dietary targets. Main things I have done is:

1. Change my eating habits. I don't eat a breakfast/lunch any more. Since I work from home full time now and no longer have a lunch time I tend to graze during the day. I wake up with black coffee and sipping on that normally keeps my body content until about 1030-11. From there I'll just start eating small 100-200 calorie "snacks" as I get hungry during the day. Since it's just me eating during this time it's almost always Carb free. Lots of Tuna. Chicken breasts. Salmon. Salads. Omeletts. Nuts. Is it possible to eat too much Tuna? I tend to eat at least one portion of Tuna a day. I get a lot of the pre-seasoned Tuna packets and stick them on a crunchy lettuce wrap with some Pico.



I also really like the Starkist Tuna creations microwave pouches, about 160-170cal a pouch.

LINK

2-3 "meals" like this will keep me content through the work day. So 400-600 calories.
I've found since my body has gotten used to these more frequent smaller meals over the last month it takes a lot less food to get my to feel "full" than it used too.

For dinner I will normally eat what I want but I try to limit my portion size.

2. Eliminate carbs and sugars as much as possible. Meaning breads, sugars, pastas, rice, etc. I cut out sugar drinks a long time ago (except sweet tea) but now eliminated sweet tea and sugar in my coffee. I'm no Keto or Zero carb. If we make a family dinner that has pasta or rice I will eat the pasta or rice, I just try to really limit how much of it I eat. If I have a long bike ride planned I will let myself splurge on carbs.

What I don't know is if I have been doing a healthy approach to dieting. I don't really know much about dieting I just sort of did #1 and #2 probably based on click bait headlines I remember reading a long time ago and every diet seems to cut out carbs. This morning I weighed myself at 190lbs. So in 5 weeks I've lost about 13 lbs. I haven't measured myself but some pants I put on yesterday were quite a bit looser than they were last month. What I've been doing seems to be working with minimal effort. But am I doing this in a healthy way? I never started with a caloric goal in mind but once I started adding it up I've been running on pretty low calorie intake. Is this healthy to do? Will it somehow screw up my metabolism? What about eating too much Tuna or Salmon? If I'm running a calory deficit do I really need to cut carbs? Fasting until 1030-11 every day is that good or bad? You guys seem very knowledgeable on all things diet and health. Maybe you can point out what I've been doing right and if there is anything I am doing wrong or could improve upon with y "diet"