It is absurd with a triangle to claim one corner is more important than another - however, at the risk of undermining our own analogy - sleep, rest and stress relief might be the most important "cornerstone" of our triangle. They are vital to your recovery. Let us repeat that - you cannot regain healthy blood sugar readings when you are sleep deprived. Sitting up late not only encourages the kind of eating that makes you ill, but the very fact you are tired will spike your blood sugars regardless of your diet or your exercise levels.
The dawn phenomenon is a normal part of waking. Our cortisol levels (stress hormones, though stress is not the right word here, remember this is normal) begin to rise before we wake up. When we release cortisol we always release a little glucose into our blood from our liver. It's like our own internal "pick me up" to get us up and moving. When your are tired it takes more glucose and cortisol to get you up, in fact one of the ways your body will try to cope with tiredness is to keep your sugars a bit higher all day. No biggie if you are not diabetic, but if you are, then you can start the day with high sugars just because you are tired.
So sleep is DIRECTLY correlated to good blood sugar control. It's not a side player, or a minor factor, it is absolutely key. And just to top things off, the other side effect of sleep deprivation is...... yep - food cravings. Ha! We're not finished. Along with higher sugars, and more cravings, there is another little bitter twist, when your sugars are higher you will tend to be hungrier and want sugary or fatty foods more also. So you now have two mechanisms, not one, driving your cravings.
Did you think it was self sabotage, or your lack of moral fibre that drove your cravings? Bah humbug! Feeling tired, hungry and stressed is a very physiological phenomenon. The best thing about all this though, is that it is not food based. If you are struggling with the old dieting mentality (you know, the "today will be different" thinking) then stress relief and sleep is the place to begin. Give yourself an easy win on your path to recovery, and pay more attention to getting your rest.