What Happens if You Eat Nothing but Veggies for a Week?

November 5, 2025 •

4 min read

According to a study published in the American Journal of Clinical Nutrition, focusing solely on plant-based foods can improve certain health markers. So, what happens if you eat nothing but veggies for a week, and what are the benefits and drawbacks of such a short-term dietary change?

Quick Summary

A week-long, vegetable-only diet can lead to weight loss, improved digestion, and increased micronutrient intake. However, it can also cause digestive discomfort and significant deficiencies in protein, healthy fats, and essential vitamins like B12, making it unsustainable for the long term.

Key Points

Initial Effects: A week of eating only vegetables can lead to increased fiber intake, better hydration, and an initial energy boost due to nutrient density.
Rapid Weight Loss: You are likely to experience some weight loss, but much of this is water weight and not a sustainable or healthy long-term strategy.
Nutrient Deficiencies: A vegetable-only diet is severely lacking in critical macronutrients like protein and healthy fats, as well as essential micronutrients like Vitamin B12 and iron.
Digestive Side Effects: A sudden increase in fiber can cause digestive distress, including gas, bloating, and cramps, especially for those not accustomed to a high-fiber diet.
Energy Crash: After the initial flush of nutrients, the lack of sufficient calories and macronutrients will likely cause fatigue and a significant drop in energy.
Unsustainable Approach: This diet is not a long-term solution due to its restrictive nature and potential for rebound eating; a balanced, diversified plant-based approach is superior.
Gradual Reintroduction: After the week, it is crucial to gradually reintroduce other food groups to avoid overwhelming your digestive system.

The Initial Changes and Benefits

Switching to an all-vegetable diet for just one week can have immediate and noticeable effects on your body, particularly concerning digestion and hydration. This dietary shift, sometimes adopted for weight loss or as a 'detox' cleanse, significantly increases your intake of fiber, vitamins, minerals, and antioxidants.

Potential Positive Effects

Improved Digestion: The dramatic increase in dietary fiber can promote regularity and improve overall gut health. Many people report feeling less bloated and more 'cleansed' as their digestive system processes the high fiber content.
Hydration Boost: Vegetables have a high water content, which naturally increases your hydration levels throughout the day. This can lead to clearer skin and better bodily functions. Proper hydration is crucial for the kidneys, which play a major role in detoxification.
Increased Nutrient Intake: You will flood your system with micronutrients, including vitamins C and K, and various antioxidants. This can help combat inflammation and potentially reduce the risk of certain chronic diseases over time.
Temporary Weight Loss: The low-calorie density of most vegetables, combined with their high fiber and water content, can lead to a calorie deficit and subsequent weight loss. However, much of this initial weight loss is likely to be water weight.

The Risks and Drawbacks of a Veggie-Only Diet

While a week of intense vegetable consumption might seem healthy, it poses considerable risks due to its restrictive nature. The lack of variety across all food groups is a significant concern for health professionals.

Nutritional Deficiencies

Protein and Healthy Fats: Vegetables alone do not provide sufficient protein or healthy fats. Your body needs these macronutrients for muscle repair, hormone production, and overall cellular function. A deficiency in these areas can lead to a drop in energy levels and even muscle mass loss.
Vitamin and Mineral Gaps: Many essential vitamins and minerals are absent or not easily absorbed from a veggie-only diet. These include Vitamin B12, Vitamin D, calcium, and iron. Over the long term, these deficiencies can have serious health consequences.

Potential Negative Effects

Digestive Distress: The sudden and massive increase in fiber can overwhelm your digestive system, leading to gas, bloating, and stomach cramps. This is particularly true if your prior diet was low in fiber.
Low Energy Levels: While some may experience an initial energy boost, low caloric intake and a lack of proper macronutrient balance will likely result in a significant drop in energy. This can cause fatigue, weakness, and make daily activities difficult.
Cravings and Rebound Eating: The restrictive nature of the diet can trigger intense cravings for fats, proteins, and carbohydrates. This often leads to rebound eating after the week is over, potentially undermining any initial weight loss or health benefits.

Comparison: Veggies-Only vs. Balanced Plant-Based Diet


Feature	Veggies-Only Diet (One Week)	Balanced Plant-Based Diet (Long-Term)
Macronutrients	Deficient in protein and fats.	Includes protein from legumes, nuts, and seeds; fats from avocados, nuts, and seeds.
Nutrient Variety	High in some micronutrients but deficient in others like B12, D, and iron.	Provides a full spectrum of nutrients with careful planning and potential supplementation.
Satiety	Low calorie density can lead to persistent hunger.	Fiber, protein, and healthy fats contribute to feeling full and satisfied.
Sustainability	Not sustainable for long-term health; risk of burnout and rebound.	A sustainable lifestyle choice with numerous long-term health benefits.
Side Effects	Potential for gas, bloating, fatigue, and intense cravings.	Generally positive, with improved digestion and energy levels once adjusted.

Making Your Vegetable Week Safer and More Effective

If you're still determined to do a week-long, veggie-focused reset, incorporating a few strategic elements can mitigate some of the risks. Always prioritize hydration and listen to your body.

Smart Additions for Short-Term Balance

Include Legumes: Lentils, beans, and chickpeas are excellent sources of plant-based protein and fiber, providing more substance to your meals.
Incorporate Healthy Fats: Avocados, nuts, and seeds are packed with healthy fats that support brain function and hormonal balance. A handful of almonds or a serving of avocado can make a big difference.
Add Whole Grains (Limited): Whole grains like quinoa or brown rice can provide necessary carbohydrates for energy, especially if you are physically active.

Your Weekly Veggie Plan (Modified)

Day 1-3: Prepare your body by gradually reducing processed foods and increasing vegetables. Start the day with a green smoothie and incorporate steamed veggies for lunch and dinner.
Day 4-5: At this point, you may feel an initial energy dip. Focus on filling, fiber-rich vegetables like sweet potatoes and leafy greens. Consider adding lentils for extra protein.
Day 6-7: Maintain your high veggie intake, but include a handful of nuts or seeds to help with satiety. Stay well-hydrated with water and herbal teas.
Transitioning Out: After your week, slowly reintroduce other food groups like lean proteins and healthy grains to avoid digestive shock.

Conclusion

While a week of nothing but veggies offers a nutrient-dense reset that can kickstart improved dietary habits, it is not a sustainable or nutritionally complete long-term solution. The experience can highlight the power of whole foods, aid in weight loss, and improve digestion, but the lack of balanced macronutrients and essential vitamins poses a risk of fatigue and deficiencies. For lasting health, the best approach is to transition from a restrictive, veggies-only week to a well-planned, balanced plant-based diet that includes legumes, nuts, seeds, and whole grains. Always consult a healthcare provider or nutritionist before making significant changes to your diet to ensure it is right for your specific needs.

Visit Healthline for more on vegetarian nutrient deficiencies

Frequently Asked Questions

Yes, it is possible to survive a week on vegetables alone, as the body can tolerate a short period of nutritional imbalance. However, it is not recommended due to the potential for fatigue, cravings, and deficiencies in protein and healthy fats.

While you might feel an initial boost from increased nutrients, your energy will likely drop significantly as your body lacks sufficient protein, fat, and calories for sustained energy production.

You will likely experience some weight loss due to lower calorie intake and a decrease in water weight. This is not a healthy or sustainable method for long-term weight management.

Yes, risks include digestive issues like gas and bloating, muscle mass loss, fatigue, and deficiencies in essential nutrients such as protein, iron, and vitamin B12.

To make a short-term cleanse safer, incorporate other plant-based whole foods like legumes (beans, lentils) and healthy fats (avocado, nuts) to provide protein and other missing macronutrients.

No, a vegetable-only diet is far more restrictive and less balanced than a standard plant-based diet. A balanced plant-based diet includes a wide variety of foods like legumes, grains, and seeds to ensure complete nutrition.

After the week, it's best to gradually reintroduce other food groups to your diet. Start with easily digestible items and slowly add whole grains, lean proteins, and more variety to your meals.