Do Not Wait for Constipation to Take Action: Four Early Signs Your Diet May Be Low in Fiber

A diet lacking in fiber often leads to constipation. Persistent constipation is more than an inconvenience. Over time, it can increase the risk of complications such as hemorrhoids. The body, however, usually signals fiber deficiency before constipation develops. Recognizing these early indicators allows you to make dietary changes before discomfort and digestive strain occur.

Fiber: The Body’s Natural Clean-Up Crew

1. Unexplained fatigue, particularly after meals

If you find yourself feeling unusually tired, especially in the hours following a meal, your fiber intake may be insufficient. Large fluctuations in blood sugar — sharp rises followed by steep drops — can cause post-meal drowsiness. Fiber helps moderate these fluctuations by slowing carbohydrate absorption. While most people associate fiber with digestive regularity, it also supports cholesterol management and metabolic balance.
A common pattern is consuming most vegetables at dinner, leaving breakfast and lunch low in fiber. This imbalance can lead to unstable blood sugar levels during the workday, contributing to fatigue. Including fiber-rich foods such as oats, berries, whole grain bread, or chia seeds in your morning and midday meals can help stabilize energy.

2. Recurring lower abdominal bloating

Occasional bloating is normal, but frequent bloating — several times a week — may indicate fiber deficiency. Inadequate fiber can disrupt the balance of gut bacteria. When harmful bacteria become dominant, they produce excess gas, leading to bloating and discomfort. Adequate fiber intake helps nourish beneficial bacteria and supports a more balanced gut microbiome.

3. Dull skin tone or frequent breakouts

You may be familiar with the gut-brain connection, but there is also a gut-skin connection. Skin health often mirrors digestive health. Low fiber intake can influence skin appearance before constipation symptoms arise. Common early signs include more frequent acne or a loss of natural skin radiance. To address this, increase fiber-rich foods and include anti-inflammatory, antioxidant-rich options such as blueberries, matcha, and turmeric to further support skin vitality.

4. Small, hard stools

Bowel movement frequency varies by individual. For men, one or more bowel movements daily is common; for women, once daily is typical, though some women with smaller food intake may pass stool every two to three days without concern. Stool form and ease of passage are better indicators of digestive health than frequency alone. Small, hard stools that require straining are an early warning sign of constipation, often linked to low fiber intake.

How Much Fiber Do You Need?

Current recommendation is 25 grams of fiber daily for adult women and about 38 grams for adult men¹. Meeting these targets requires including fiber at each meal and snack; eating vegetables at dinner alone may not provide enough. For example, 1 cup of cooked broccoli provides roughly 5.2 grams of fiber — far below daily goals for both gender.

High-fiber food sources include:

• Whole grains such as oatmeal, whole wheat bread, and brown rice
• A variety of vegetables and fruits
• Nuts and seeds, which also provide protein
• Legumes such as chickpeas, lentils, and canned black beans

Increase fiber intake gradually and drink adequate fluids to help your digestive system adjust. By paying attention to these early warning signs and making consistent dietary changes, you can support digestion, stabilize energy, and promote overall health long before constipation becomes a concern.

1. Institute of Medicine. 2005. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press. https://doi.org/10.17226/10490 .