The first big event first lady Michelle Obama’s campaign to fight childhood obesity came this week with the announcement that leading food processors are joining the battle, committing to collectively reduce 1 trillion calories from their offerings in the next two years.

While it sounds promising, we are skeptical.

These companies are in the business of selling products, not protecting our health. It may be bad for business to get a reputation for killing your customers, but the reputation can be fixed while still falling short of Obama’s health goals.

The reality is that obesity is a complicated problem that involves genetics, culture and personal choice. But it’s also affected by the availability and promotion of processed foods that are high in fat, sugar and carbohydrates and that are chemically engineered to make you want more and more.

Much of Obama’s early statements about the obesity problem stressed exercise, which is important to maintaining a healthy weight, but won’t get you there if you eat too much.

A person who drinks 7-Eleven’s 64-ounce Double Big Gulp cola would need to go for a two-hour bicycle ride or run for six miles to burn off the calories. This is a problem that is not going to be solved through exercise alone.

It’s not going to be solved solely through public education, either, although that too is important. The food industry is too good at making us want its products.

Childhood obesity is not only an expensive problem for our health care system now, it is one that challenges our future as a nation.

Obama should keep the pressure on the food industry and be prepared to push harder if these pledges don’t show results.