@maga Thank you for the exercise! I am very lucky to have an established meditation practice. Like the timer you mentioned I have a mindfullness bell that chimes every 15 minutes. When it chimes I completely stop what I’m doing and just focus on my breath. I was actually going to be a Buddhist nun but then I met my husband and well… some vows I couldn’t take… 
Feeling great is wonderful! But feeling horrible, sad, anger and the whole pantheon of emotions is awesome too. It’s a miracle to have emotions! I practice, sometimes not very successfully, to just experience my emotions as they are, in that moment, without judgement or preconceived notions.
I do enjoy remembering all of my memories: the wonderful and horrific. How I have chosen to respond to those events and memories manifests my values, character, actions and habits. However, I do not have any “end” goals. I just want to be alive and present in this moment- It’s literally all the time we have. My only “aim” is to bring joy, compassion, and empathy into this world. I do that by cultivating that within myself and doing what I can to listen deeply to others.
My big “why” doesn’t really have much to do with my weight. Sometimes I’ll be overweight sometimes I’ll be dangerously thin. I have a serious illness that knocks me out every couple of years so I just want to keep this body healthy enough to cope with the next round of six feet under. I’ve made a promise to my family that I’ll fight for life as long as possible.
Buddhist (generally) only eat 1 or 2 meals a day in a restricted time window (traditionally between dawn and noon). (This is not the case if you are ill). This is not only part of the Dharma or middle path but has historical/societal/ traditional significance for the time and place it became a practice. I do not fast for weight loss, though it does assist in that. For me it is primarily spiritual and the weight/ketones are fun data points. I have brain damage from not sleeping and am not able to remember many years of my life and it is difficult for me to make new memories/ i have a distorted perception of time. I am trying keto because research shows that it may reduce risks of all sorts of things I’m going to probably have sometime. I like knowing how all things are interconnected- inter-are. It’s also important for me to have all of those data points for my doctors. I am very closely monitored by specialists and we have to act immediately (with all relevant data) if anything causes my systems to go “out of whack” so to speak.
As far as Buddhism or Zen goes a wonderful place to start is just with mindfulness. A secular author that I love is John Kabat-Zinn. I resonate with the teachings of Thich Nhat Hahn the most. He is a Vietnamese zen monk. A delightful, simple, short, and profound book to start with is “Peace Is Every Step” by Thich Nhat Hahn.