Whenever someone asks about nutrition and training, the first thing I recommend that they do is to make small changes to their daily eating habits. It's not uncommon to see someone lose up to 10lbs in one week just from eliminating soda and other calorie-containing drinks.
Other calorie-containing drinks that I see people frequently consuming include fruit juices (even all-natural juices), sweetened tea, milk, Gatorade and other sports drinks and coffee drinks from Starbucks and other vendors. These drinks tend to be loaded with sugar and fat (even trans fats - something you want to avoid at all costs) and tons of calories. These are health and diet destroyers and will leave you wondering what went wrong when you don't notice any differences in the mirror or with how your clothes fit.
If you are beginning to take steps to get your nutrition, health and fitness on track, I highly recommend that you begin cutting out all soft drinks (even diet) and the coffee drinks (yes, all of them!).
So what should you drink? Water. Yes, get used to drinking water. If you have problems drinking water because there isn't enough taste, try adding a little lemon to your water. Also, cold water tends to be better than warm water or room-temperature water.
If that still doesn't do the trick, I'm okay with using Crystal Light in small quantities. The other thing you should drink more of is green tea. There have been many health benefits reported from those who drink green tea. It doesn't have to be a special brand. From what I've read, Lipton Green Tea is a great brand and good quality. If you need to sweeten it up, I recommend using Splenda or Xylitol.
What about cheese? As for cheese, you should eat it. However, let me tell you that cheese can be high in fat and calorically dense. Even though most of the fat is good fat, it still packs quite a punch. So my suggestion is to be careful of your portion sizes. Typically one ounce is a serving. That's not a huge amount, so you just have to be mindful of that. Avoid non-fat and reduced-fat cheeses and stick with real cheese (low-fat and non-fat cheeses do not absorb nutrients as well because the body needs fat for proper digestion and absorption).
Yogurt is good for you, and I highly recommend that you eat it for the wonderful live cultures it contains. It helps with digestion and has many beneficial bacteria. As for the type and brand, try to avoid all the sugar-filled ones such as "fruit on the bottom." They are packed with a ton of calories and sugar.
Organic and Greek yogurts are best. Try to find a brand that contains less than 20 grams of carbs from sugars. And be sure to avoid any products that contain the most evil sugar substitute in the world: High Fructose Corn Syrup (HFCS).
That is something you should look for in the foods you buy - HFCS. If it's in the ingredient list, don't buy it. For some products, it's hard to avoid unless you buy things from whole food stores and natural food places (this applies to bread - as almost all store-bought bread has HFCS).
Locally, you can go to Ward's or Mother Earth and get freshly made, natural bread that only has a few ingredients and uses molasses and brown sugar as the sweetener. That is much healthier than high fructose corn syrup. Remember to try and save the bread for breakfast and post-workout when your body can better utilize the carbohydrates rather than storing them as fat.
HFCS has been linked to diabetes and obesity. It is in millions of products and people consume tons of it on a daily basis and don't understand why they are getting fat or having health problems.
Start reading labels when you buy things. The first three or four ingredients are typically the majority of what the item contains. Also, don't forget to look at serving sizes. Many people buy a 20oz Coke or Gatorade and drink the whole thing. If you look at the label, that's typically 2.5 servings so that 150-calorie soda just turned into 375 calories for a 20oz drink. Just imagine the people drinking soda from fast food joints. They are typically 32 ounces and 600 calories!
Diet sodas are not any better even though they contain 0 calories and 0 carbs because there are other ingredients in diet sodas that are bad for you (the enamel on your teeth) and they tend to cause people to gain weight because of the way the sweeteners are structured (chemically altered). So you may think a 0-calorie drink is an okay substitute, but it could cause weight gain nevertheless.
Remember to make small changes each day. Over time, they add up to big changes in the mirror and the way you feel.