Assume you have little willpower, and set up if and then statements.

a) Little willpower: we react to our environment. Think you have limited willpower then act to create an envrionment which supports your good behaviors.

b) Plan using 'if then' thinking. Studies show that this conditional approach is the key to getting things done.

For example, If I see the delicious unhealthy item on sale for $5 at Store X, then I do behavior Y.