TheStreet's Jim Cramer says there are seven investment themes investors should consider before buying a stock. The second theme is 'companies that keep us healthy.' Cramer likes WhiteWave Foods (WWAV) and Sprouts Farmers Markets (SFM). Cramer says another stock which you might consider is Whole Foods Markets (WFM) but its growth is not as great as the other two. Cramer is a little cautious on Chipotle because he feels shares are overpriced. Cramer says eating healthy can make you wealthy.