Yes, sugar is toxic. It was never found in a natural diet for humans in the high quantities it is now ingested by people. The two major effects it has on the body is: 1) simultaneously raising blood sugar levels while promoting insulin resistance when it is eaten, and 2) promoting the glycation process that badly affects metabolic processes. Do a google search on "Advanced Glycation End Products" (also called AGEs) for a better understanding of what exactly sugar does to you.
If you cut the highly processed carbs (sugar and wheat based snack foods primarily) from your diet, you will stop having the 2-3 hour cycles of hunger, energy rush, crash, and food cravings. Once your body has corrected itself, you will no longer need to eat for "high short term energy". Think about human history for a minute and consider whether it would be an advantage for hunter-gatherers to have to stop and eat every couple hours. The fact that everyone generally does now and that people living on traditional diets like the Masai of Africa do not should tell you something.
While it is an aside, getting enough sleep will also reduce your necessary daily food requirements by about 400 calories.
If you cut the highly processed carbs (sugar and wheat based snack foods primarily) from your diet, you will stop having the 2-3 hour cycles of hunger, energy rush, crash, and food cravings. Once your body has corrected itself, you will no longer need to eat for "high short term energy". Think about human history for a minute and consider whether
While it is an aside, getting enough sleep will also reduce your necessary daily food requirements by about 400 calories.
Eat natural fats - butter, coconut oil, animal fat (lard) and natural food with high fat content - bacon, eggs... You won't have energy ups-downs and you will feel strong and satisfied (drop sugar and flour).
Unprocessed starch, as in brown rice or oat, or fructose (bananas etc.). Potatoes, white rice, and most fruits will give you an even shorter term energy boost, spiking your blood sugar more sharply. By sugar, people normally mean processed sugar; they do not mean starch or fructose found in vegetables or fruit.