Expert Q&A

Lost 3 and a half kg in my first 3 days…is this normal and the role of cortisol and stress hormones

Understanding Your Rapid Early Weight Loss

Losing 3.5 kg in the first three days is common but rarely reflects true fat loss. In my 20 years guiding thousands through the CFP Weight Loss program, I've seen this pattern repeatedly. Most of that drop comes from water weight and depleted glycogen stores. When you reduce carbohydrates and sodium while increasing water intake, your body releases stored fluid—often 2-4 pounds in 72 hours. True fat loss averages 0.5-1 kg per week for sustainable results, especially for adults aged 45-54 facing hormonal changes.

The Critical Role of Cortisol and Stress Hormones

Cortisol, your primary stress hormone, directly influences abdominal fat storage and metabolic rate. Chronic elevation from past diet failures, joint pain, or daily pressures raises insulin resistance, making weight loss harder despite your efforts. In the opening days of a new plan, reduced calories can temporarily spike cortisol if your body perceives it as a threat. This explains why many feel fatigued or retain belly fat even as the scale drops. My book, The CFP Weight Loss Method, details how stabilizing cortisol through balanced macros (40% protein, 30% healthy fats, 30% low-GI carbs) prevents this rebound. For those managing diabetes and blood pressure, monitoring morning cortisol via simple saliva tests can reveal if stress is sabotaging progress.

Is This Pattern Safe for Beginners Over 45?

For complete beginners with joint pain and middle-income realities, this initial drop can motivate but risks muscle loss if not managed. Insurance rarely covers programs, so self-guided approaches like CFP emphasize time-efficient strategies: 20-minute daily walks instead of gym sessions, and 5-ingredient meal templates requiring under 15 minutes prep. Rapid loss beyond 2 kg weekly often signals dehydration or excessive restriction, potentially worsening hormonal changes like perimenopause-related estrogen decline that slows metabolism by up to 15%. Focus on consistency over speed—aim for 0.5-1% of body weight lost weekly to preserve lean mass.

Actionable Steps to Turn Early Wins Into Lasting Success

1. Replenish electrolytes with 400mg magnesium, 300mg potassium daily to stabilize fluid balance and reduce cortisol spikes. 2. Prioritize 7-9 hours sleep; poor rest elevates cortisol 30-50%. 3. Track waist measurements alongside scale weight—fat loss shows here even if water fluctuates. 4. Follow the CFP 3-Phase Protocol: Phase 1 resets hormones with anti-inflammatory meals, Phase 2 builds sustainable habits without complex plans. Thousands in our community have reversed yo-yo patterns this way, losing 10-20 kg while improving blood pressure and energy. Start simple today: swap one high-sugar item for a protein-rich alternative and walk 10 minutes post-meal to blunt glucose spikes. Your early 3.5 kg loss is a signal—use it wisely with stress-aware strategies for lifelong results.

💬 What the Community Says

The community shows mixed but largely positive reactions to losing 3-4 kg in the first few days. Most practitioners recognize it as mostly water weight and feel encouraged rather than alarmed, especially those over 45 who have failed multiple diets. A common theme is surprise at how quickly the scale moves when cutting carbs, with many sharing stories of 5-7 pound drops in 72 hours followed by slower, steadier progress. Debates center on cortisol: some report feeling more stressed and retaining belly fat despite the numbers, while others note improved energy once they added magnesium and sleep routines. Beginners managing diabetes or joint pain frequently mention embarrassment asking doctors, turning instead to forums for validation. A vocal minority warns against celebrating too early, citing past rebound weight gain, but the overall sentiment celebrates the initial momentum as long as realistic expectations follow. Many appreciate straightforward advice avoiding complex meal plans, aligning with middle-income lifestyles where insurance won't help.
Clark, R. (2026). Lost 3 and a half kg in my first 3 days…is this normal and the role of cortisol . *CFP Weight Loss*. https://blog.cfpweightloss.com/ask/lost-3-and-a-half-kg-in-my-first-3-days-is-this-normal-and-the-role-of-cortisol-and-stress-hormones
Russell Clark, FNP-C, APRN
About the Author

Russell Clark, FNP-C, APRN, is the founder of CFP Weight Loss in Nashville and CFP Fit Now telehealth. Over 35 years in healthcare — Army Nurse Reserves, Level 1 trauma ER, hospitalist — he developed a 30-week protocol integrating real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 30–90 pounds. He and his wife Anne-Marie lost a combined 275 pounds using the same protocol.

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