how to keep a food log

Set up your diary. The simplest way to track what you eat and drink is by setting up your diary in a notebook or downloading a food journal app on your phone. You’ll need to be able to keep track of the date, time, place, item eaten, quantity consumed, and extra notes.
If you like to write things down by hand, use a blank notebook or purchase a daily diary with enough space on each page to record your intake for the day. You can even search online for sample food dairy pages that you can print and use or copy into your notebook.
You can use an app or an online tracking device if you prefer. Since food journaling has become so popular, there are a variety of good apps to choose from.

Record everything you eat and drink. The most accurate food journal will most likely be the most helpful as well. Try to jot down or take note of everything that goes into your mouth. Include all meals, drinks, snacks and even nibbles of food you eat while you cook.
Be very specific, and break complicated foods down by ingredient. For example, instead of writing down “turkey sandwich,” write out the quantity of bread, turkey and condiments as separate entries. Handle other mixed foods, like casseroles and smoothies, in a similar way. This will help you remember what is in foods or the total amount of calories.
Don’t forget to record snacks or random odds and ends you eat, like a cookie offered at work.
Record all beverages. Don’t forget to track your total water intake as well. Tracking how much water you drink will give you insight into whether or not you need to consume more water to help you stay hydrated.

Write down accurate quantities. If you’re concerned about how many calories you consume, writing down the quantities you eat is important data to include in your diary. You might want to purchase a food scale or measuring cups to help ensure your quantities are correct.
Before making changes to how much you eat, start by measuring the food that you’d normally serve yourself at each meal. If the portions are too big or too small, make any necessary adjustments.
Keep measuring your foods or using cups, bowls, or other containers that are a specific measurement. This will help with the accuracy of your journal. Guesstimating or “eye-balling” is not accurate and generally leads to underestimating your total food and calorie intake.
You might have to estimate quantities when it comes to eating out at restaurants or purchasing food that’s difficult to weigh. If you eat at a chain restaurant, check online to see if you can find information on the quantities of ingredients in their serving sizes. Also try to find household items that compare with common serving sizes. For example: a deck of cards is 3-4 oz or 1/2 cup or one egg is 2 oz or 1/4 cup.
Track calories. If you’re trying to lose or gain weight, tracking your total calorie intake each day will be helpful. Some food journal apps provide calorie and nutrient information for you. If using a notebook or paper copy of a food journal, you may need to research your foods online to find the calorie is a great resource.
Start by tracking how many calories you’d normally consume in a day and then make any changes as needed.
Cutting out or adding 500 calories daily will result in about a one to two pound weight loss or weight gain