In addition to all the good advice which I would echo, what hasn’t been picked up on (I don’t think) is your food quality. You will feel exhausted if you eat poor quality food. By poor quality I don’t mean Cadbury’s dairy milk vs Green and blacks organic. I mean poor quality as in high refined sugar, high trans fat, low fibre, low nutrient density, high processed food. Even if you were to eat that kind of diet on the optimal calories your body needs in a day you would still feel exhausted.
I follow a plant based diet (vegan without the beige or processed food). I’m also a racing endurance cyclist, mum to a 4 year old and work part time in a very demanding job.
I train 10-17 hours a week on my bike. DS is very active and we have 2 full days a week together, we are out walking or he cycles and I run. Yet I’m literally bursting with energy. Why. I’d put it down to my diet. How do I know? 15 years ago. I. Was. You.
I would suggest ‘diets’ don’t work for you as you are focussing on the restrictive commercial ones. The providers don’t want them to work... that’d be a very poor business model! I accept Slimming World is slightly different as it does focus more on food quality. But as an experiment I tried doing it (just using my normal eating habits) and I was way over my daily ‘syns’ (which I used on stuff like nuts). There isn’t any facility to eat the additional calories you burn through exercise. That’s probably not important if you aren’t doing much exercise. But for someone who’s physically active (not necessarily at my level) that is bad news. Your body needs good quality food to fuel it, help it repair and recover and keep you well. Commercial diets tend to push you to thinking ‘diet’ foods are healthy as they are low calorie. They aren’t! I’m referring to stuff like diet drinks, weight watchers products etc. They are high in bad saturated fats and high in artificial flavourings and sweeteners.
I did actually ‘successfully’ complete WW many years ago. I was 4.5 stone heavier than now. I lost weight fairly quickly - 3 stone in 4 months. But looking back I shudder at my diet! I was eating low calories crisps, drinking diet drinks, eating ‘diet’ foods. I was constantly grumpy as I was operating on a calorie deficit too great for my needs. I was also tired. Hardly surprising given the poor nutrient quality food I was living on.
I piled most of the weight back on. I started cycling and gradually got more and more in to it. At the same time I gradually changed my diet. Just small regular swaps. So the crisps were replaced with nuts. Low calorie cereal for porridge. Etc. It took several years. But because I made small regular changes, they were sustainable. The weight fell off me! My energy levels kept increasing which fired me on.
Occasionally I’ll have a ‘beige’ day. My energy levels drop. My body retains water for several days. I get heart palpitations from the refined sugar. I feel sluggish and almost depressed for several days.
I now view food as ‘fuel’ so it needs to benefit me (be nutrient dense) in order for me to eat it. I couldn’t ever imagine returning to my old ways.
The important thing with a successful diet is that attitude change and sustainable habit change. It’s got to be sustainable and enjoyable. Early days I found food swaps I really enjoyed. I discovered a sheer love for nuts and dried fruit. I found them waaay more enjoyable than the walkers baked and mcvities digestives that I swapped from.
MyFitnessPal is ace! It’s not just about good diet quality but getting your macro nutrients (fibre, protein and carbs) in order. If the balance is too far skewed in favour of one it’ll likely cause low energy.
Good luck. You can do this. See it as a lifetime thing to help you maintain optimal health.