Fish meal, wheat flour, soy flour, fish oil, brewers dried yeast, squid meal, soy lecithin, krill meal, l-ascorbic acid phosphate (source of vitamin C),
What is the protein content? Looking at the ingredients, I'd say you should change to a different food. You want a food that has real fish products as the first few ingredients, not wheat or other grains.
My current stand on feeding is:
Split feedings into 2 meals, one in the morning and one in the afternoon.
Give a staple betta pellet with at least 40% protein. The first ingredients should be real meat products, NOT wheats. Depending on the size of the pellet, give 2-4 pellets at each feeding. If you feed smaller pellets, you might be able to safely offer 4-8 but most of these pellets are only sold online (ie atison's betta pellets).
You should supplement your betta's diet with frozen and/or live food. Freeze dried foods are not good for bettas and should never be given except as an occasional treat. Bettas will much prefer frozen food to freeze tried and frozen foods are extremely good for them. You should offer them a variety of frozen or live foods such as Bloodworms, glassworms, daphnia, brineshrimp, tupliflex, live wingless fruit flies, live mosquito larva and live black worms.
My feeding routine is:
8 Atison's betta pro pellets in the AM (they are tiny pellets so this is not over feeding, however most people would be offering 2-4 pellets in the AM) and then I rotate between frozen bloodworms, glassworms and brine shrimp in the PM. They always get their pellets and a frozen (or live food) every day.
As for the temp, water is always about 3 degrees cooler than room temp. So if your room temp is 60* like you said, then I am very concerned for them. Temps under 65* are extremely detrimental for bettas. They are very sturdy fish but temps that low are just bad. He was most likely stressed by the sudden temp change since there was at least a 5* difference. You should seriously consider getting him an adjustable heater and *slowly* increasing the temp in his tank to 78-80*. I assure you, one he adjust to the new temp, he will love it. Bettas are from Thailand, it is always hot there...
Your other betta would love a heater too. You are obviously interested in the health of your fish.. the aboslute best thing you can do for them is
1) Proper water changes
2) Good food
3) Right temp