The 3-day (Military) Diet prescribes low-calorie, specific food combinations for three days. Initial weight loss is usually water and glycogen depletion rather than fat loss. The diet is temporary, not proven to cause a lasting metabolic boost, and carries short-term side effects for some people. Those with medical conditions should consult a clinician before trying it.

What the 3-Day Diet is

The 3-day diet (often called the "Military Diet") is a short, very-low-calorie eating plan that lays out specific foods for three days, then recommends returning to a more normal intake. Promoters say the fixed food combinations trigger a metabolic reaction that burns calories faster and can produce rapid weight loss.

How it likely produces quick weight change

Short-term weight changes on this plan usually reflect reduced calories and carbohydrate intake, not sustained fat loss. Cutting carbs lowers glycogen stores; each gram of glycogen binds water, so you'll lose water weight as glycogen drops. That explains much - if not most - of the initial weight change.

The plan's menu mixes items like coffee, grapefruit, toast, canned tuna, lean meat, vegetables and small servings of ice cream. Calorie totals for each day are low compared with typical daily needs, which explains rapid scale changes.

Limits and safety concerns

There's no strong evidence that the diet triggers a special, lasting metabolic boost. Rapid weight changes from such short plans are usually temporary and often return when someone resumes a regular diet.

Possible short-term side effects include fatigue, lightheadedness, headache and strong hunger. People with diabetes, those who are pregnant or breastfeeding, people with a history of eating disorders, and anyone with chronic health conditions should avoid such restrictive plans unless supervised by a clinician.

The original advice to avoid repeating the 3-day cycle back to back and to allow days of normal eating between cycles is sensible, but there's no consensus on an exact safe interval. Follow-up with a health professional before repeating cycles.

Practical takeaway

If you want sustainable weight loss, follow a balanced, calorie-controlled plan with regular physical activity. Short, very-low-calorie diets can produce quick numbers on the scale but not reliable long-term fat loss. Use the 3-day plan only with clear expectations, and check with your physician first.

: Specific claims about "up to 10 pounds in 3 days" and typical daily calorie totals for the plan.
1: The original recommendation of a 5-day minimum gap between cycles and whether that remains advised by current sources.
2: Any authoritative safety guidance (e.g., CDC or major medical societies) explicitly addressing the 3-day/Military Diet.

  1. Verify common claim of "up to 10 pounds in 3 days" and quantify typical realistic weight change.
  2. Confirm typical daily calorie totals for the 3-day/Military Diet menu.
  3. Verify original recommendation (and any modern guidance) about waiting five days between cycles or other recommended intervals; check clinical guidance from CDC or major medical societies.

FAQs about 3 Day Diet

Does the 3‑day diet burn fat quickly?
Not likely. Most early weight change reflects water and glycogen loss from calorie and carbohydrate restriction, not rapid fat loss.
Is it safe to repeat the 3‑day diet every week?
There's no established safe schedule for repeating it. Many sources advise not doing back-to-back cycles and recommend consulting a clinician before repeating the plan.
Who should avoid this diet?
People with diabetes, pregnant or breastfeeding people, those with eating disorders, and people with chronic medical conditions should avoid it unless supervised by a healthcare professional.
Will lost weight stay off after the diet?
Often not. Because the diet is short and low in calories, regained weight is common once normal eating resumes unless you switch to a sustainable, balanced plan.