The Regimen is a more reliable way to manage acne and gives you more control by killing acne bacteria and preventing new breakouts in your affected areas. But using the Regimen while eating a sensible diet would be the optimum combo.
Drink plenty of water to purge toxins through your sweat and urine. Eat a variety of fruits and veggies which are full of antioxidants, and organic/locally grown when possible to minimize ingestion of chemicals, which can cause eczema and other health issues. Carrots are full of vitamin A which is excellent for calming inflammation. Add a good multivitamin for good measure, plus consider supplementing with D3, E, omega 3 fish oil, and 30 mgs zinc gluconate...all great for calming inflammation. Some people have noticed a spike in acne when dairy is consumed and they do better to avoid or minimize, or switch to almond milk.
Although we don't know what causes it, ultimately acne is an inflammatory response...those with chronic acne have a naturally elevated inflammatory response compared to clear-skinned people. Being proactive with managing inflammation can help in the long run and even help resolve acne in some cases.
Just some things to consider. Overall, the Regimen should keep you clear even without diet changes, but most agree you're still better off avoiding the junk food.
Hope this is helpful! 
