Poor eating habits can contribute to stress by causing weakness. fatigue. difficulty concentrating all of the above.

## Step 1<br />The problem is asking us to identify the effects of poor eating habits on stress. The options provided are weakness, fatigue, difficulty concentrating, and all of the above.<br /><br />## Step 2<br />We need to understand that poor eating habits can lead to a variety of health issues, including weakness, fatigue, and difficulty concentrating. These issues can contribute to stress.<br /><br />## Step 3<br />Weakness and fatigue are physical symptoms that can result from poor eating habits. When the body does not receive the necessary nutrients, it can lead to a lack of energy and strength, which can cause weakness and fatigue.<br /><br />## Step 4<br />Difficulty concentrating is a mental symptom that can also result from poor eating habits. When the body is not receiving the necessary nutrients, it can affect the brain's ability to focus and concentrate.<br /><br />## Step 5<br />Given that all the options provided are potential effects of poor eating habits on stress, the correct answer is "all of the above".