It's been said often already but I'll say it one more time: it's the sugar. There's lots of contributing factors and details, for instance I find a lot of meat to be a culprit, or processed foods, or wheat, but what I believe it comes down to for most people is sugar. (at least in USA) there is SO MUCH sugar in everything it's crazy IMO. Liquid sugar definitely a big culprit.
If you'd like a compare, I'm also about 5'7", about 8% body fat, and in my 40's. Personally for my diet:
Breakfast: oat cereal, I look for things only with 10g sugar or less (near impossible). For me Natures Path Organic Pumpkin Seed & Flax
Lunch: veggie wrap with feta cheese and a little bit of chicken (one breast lasts me the work week)
Dinner: something low or no meat. Examples of late are fish, rice & lentil tacos, black bean soup, egg sandwich, pizza sometimes. Side of veggies always and sweet potatoes sometimes.
Snacks: during the day I have yogurt; I buy unsweetened yogurt, add a little honey, fruit, and cinnamon. I used to get a sweetened yogurt which had something like 22g sugar per serving! 3-4 granola snack bars thru the work day, again with 10g or less sugar. Nighttime snack is raw veggies and smoked salmon.
Drink: coffee in the morning, lots of green tea through the day, and water. On a rare occasion I'll have a small Gatorade after a soccer session.
Lastly, when I started cutting back sugar and went more plant based vs meat based, my energy levels shot up quite a bit!