One of the best indicators of human well-being is life expectancy. High life expectancy means low infant mortality. It also, almost invariably, correlates with high access to food, medicine, shelter, and education, and low levels of disease and violence. So in looking at the impact of economic growth on the developing world, it's worth looking at what correlates with high life expectancy. And it's clear that both high income and high energy use come hand in hand with high life expectancy.
On a log scale, income per person correlates quite well with life expectancy around the world. There are some notable outliers, like South Africa, but those are the exceptions rather than the rule. You can find more at Gapminder.
It's also clear on a global basis that greater access to energy correlates to greater life expectancy. From Roger Pielke Jr's blog.
For these reasons, from a humanitarian standpoint, we should welcome the developing world growing richer and increasing their access to energy, even as we work to find ways to reduce and reverse the environmental damage caused by current forms of energy use.