Unsweetened coffee

Researchers at Harvard tracked over 100,000 people for about 20 years. They concentrated on a four-year period, and their conclusions were later published in this 2014 study. They found that people who increased their coffee intake by over one cup per day had an 11 percent lower risk of developing type 2 diabetes.

It's crucial that your coffee be unsweetened, just like with tea. Coffee with milk, cream, or sugar has more calories overall and could have an impact on your blood sugar levels. For example, creamy, sugary drinks found at cafe chains are often loaded with unhealthy carbs. They’re also very high in calories. You have a lot of options for low- or no-calorie sweeteners if you decide to drink them.