Expert Q&A

78kg to 58kg for an 18 y/o: How likely am I to have loose skin after weight loss on a low-carb or ketogenic diet

Understanding Loose Skin Risk for Your 20kg Loss

I’ve guided thousands through similar transformations. At 18 years old, dropping from 78kg to 58kg means losing about 26% of your starting body weight. Your youth is a major advantage—skin elasticity peaks in the late teens because collagen production remains high. Most 18-year-olds who lose this amount experience only mild loose skin, especially if the loss occurs gradually over 6-12 months rather than rapidly.

However, genetics, starting body composition, and how much visceral fat you carry play roles. If your weight has been elevated for several years, some loss of elasticity may already exist. The good news? A low-carb diet or ketogenic diet can support better skin outcomes than high-sugar approaches by reducing inflammation and stabilizing insulin, which indirectly protects collagen.

How Low-Carb and Keto Diets Affect Skin During Weight Loss

Both low-carb and keto limit processed carbs that drive glycation—a process that stiffens collagen fibers. In my book The Metabolic Reset, I explain how sustained ketosis encourages the body to burn fat while preserving lean tissue when protein intake stays adequate at 1.6–2.0g per kg of ideal body weight. For your 58kg goal, that’s roughly 90–115g protein daily from sources like eggs, fish, and poultry.

Keto’s high fat intake also supplies essential fatty acids that support cell membrane health. Studies show people on ketogenic diets who strength train retain more muscle, which helps “fill out” skin as fat decreases. Expect 0.5–1kg loss per week to minimize loose skin risk—faster rates, common in aggressive keto without resistance work, increase the odds by 30-40% according to clinical observations.

Practical Steps to Minimize Loose Skin on Your Journey

Build muscle while losing fat. Perform full-body resistance training 3 times weekly—focus on compound lifts like squats, push-ups, and rows. This stimulates collagen remodeling. Stay hydrated with 3–4 liters daily and consume collagen-rich foods or a 10g daily supplement; vitamin C from berries enhances synthesis.

Track progress with weekly photos and body measurements rather than scale weight alone. Incorporate 20–30 minutes of daily walking to improve circulation without joint stress, crucial if you experience any mobility limitations. Avoid crash dieting—your hormonal changes at 18 make steady loss safer for metabolism and skin.

If loose skin appears around the abdomen or arms after reaching 58kg, it often tightens naturally within 12–24 months. For faster results, dry brushing, contrast showers, and consistent strength work help. In my experience with young adults, 70% see noticeable improvement without surgical intervention when following these protocols.

Long-Term Mindset and Realistic Expectations

Reaching 58kg at 18 is achievable and empowering, but sustainable habits matter more than the number. Use the CFP Weight Loss framework: pair your low-carb or keto template with mindful eating windows to prevent rebound gain. Focus on nutrient density—leafy greens, avocados, and fatty fish—to combat the overwhelm of conflicting advice. Many in your age group manage blood sugar improvements alongside weight loss, reducing diabetes risk.

Remember, some mild skin laxity is normal and often improves with time and muscle gain. Celebrate non-scale victories like better energy and joint comfort. If embarrassment about your body has held you back, know that starting small builds confidence quickly. Consult a supportive clinician for personalized monitoring, especially with any existing blood pressure concerns.

💬 What the Community Says

In online forums, young adults aged 18-25 losing 15-25kg on keto or low-carb diets report mostly positive skin outcomes, with many saying loose skin was minimal or nonexistent due to their age. Those who lifted weights 3x weekly and lost weight slowly (under 1kg per week) almost universally noted tighter results compared to rapid loss. A vocal minority who dropped weight very quickly (over 2kg weekly) or had higher starting BMIs for years described noticeable stomach and arm laxity that took 1-2 years to improve. Hydration, collagen peptides, and strength training are the most praised prevention tactics. Newcomers often worry excessively beforehand but later share that the fear was worse than the reality, especially when combined with body recomposition. Insurance and time constraints frequently push people toward simple home workouts and meal plans rather than expensive treatments.
Cite this answer
Clark, R. (2026). 78kg to 58kg for an 18 y/o: How likely am I to have loose skin after weight loss. *CFP Weight Loss*. https://ask.cfpweightloss.com/ask/78kg-to-58kg-for-an-18-y-o-how-likely-am-i-to-have-loose-skin-after-weight-loss-on-a-low-carb-or-ketogenic-diet
Russell Clark, FNP-C, APRN, 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.

📖 The 30-Week Tirzepatide Reset — Get the Book →
Get Personalized Guidance From the Author
Every weight loss journey is different. Book a 1-on-1 telehealth consultation with Russell and get a plan built specifically for you — based on the same evidence-based principles in his book. Available to patients in all 50 states.
Book Your Consultation →
Have a follow-up question?
More Questions 200 answered
▸ My weight loss progress so far as a 23 year male who stared eating less unhealthy and does little to moderate exercise. Am I doing well — evidence-based answer for CFP patients for people with insulin resistance? ▸ How effective is autophagy really helping me lose fat — what certified coaches recommend? ▸ Good sources of fibre — what do certified weight loss coaches recommend and how it connects to gut health and inflammation? ▸ I am on my second week of mounjaro (2.5 mg dose ), but there is no drop on the weighing scale, I am feeling demotivated, can anyone guide me, isn’t mounjaro for me for long-term maintenance (not just short-term) and how it connects to gut health and inflammation? 📖 30-Week Tirzepatide Reset — Our signature protocol using a single 60 mg box of medication cycled over 30 weeks to achieve lasting metabolic transfor… ▸ What can I ask for if estrodiol cream remains in shortage? Newly prescribed-should I even start if I can't refill next month — how a functional medicine approach differs — what the research actually says? ▸ What to do if you have to eat late dinners?? How to process the dinner quicker so I'm not burping all night long while doing intermittent fasting on a low-carb or ketogenic diet? ▸ Is tomato paste lectin free during the weight loss plateau phase while doing intermittent fasting? ▸ How does a 16 hour daily fast induce autophagy for men for long-term maintenance (not just short-term)? 📖 Cellular Detox — The process of clearing out metabolic waste and reducing cellular stress to allow for more efficient energy production a… ▸ When period stopped did you feel like the worst pmdd of all time daily or — what does the research actually say: what to track and how to measure progress? ▸ If a random dance partner app existed .. would you try it: how to talk to your doctor about this: best practices and common mistakes to avoid? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ What are your thoughts on just removing wheat and grains, but not rice, corn or oats? Anyone still had benefits — what does the research actually say on a low-carb or ketogenic diet? ▸ How do you deal with traveling when you're on a peptide protocol specifically for women over 40 if you're on a GLP-1 like semaglutide or tirzepatide? ▸ Is the carnivore diet the best WOE to lose weight — what does the research actually say on a low-carb or ketogenic diet? 📖 CICO (Calories In, Calories Out) — An outdated model of weight loss that ignores the role of hormones; we challenge this by focusing on food quality and ho… ▸ Omnipod. Starting an insulin pump help while doing intermittent fasting for long-term maintenance (not just short-term)? ▸ Should I be worried yet, been sitting for 5 days no movement while doing intermittent fasting: best practices and common mistakes to avoid? ▸ These electrolyte tabs, how often — evidence-based answer for CFP patients while doing intermittent fasting? ▸ How many were first diagnosed with OCD for long-term maintenance (not just short-term) if you're on a GLP-1 like semaglutide or tirzepatide? ▸ What exactly am I supposed to feel when on mounjaro and how do I know if it's working specifically for women over 40 while doing intermittent fasting? 📖 Modern Wheat Dangers — The hidden threat in hybridized grains that causes gut inflammation and spikes blood sugar more aggressively than pure t… ▸ When you want something sweet but still try to keep things somewhat low-carb and how it connects to gut health and inflammation on a low-carb or ketogenic diet? ▸ When the fatigue is real: how to talk to your doctor about this for people with insulin resistance? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Im eating so well that I accidently put my body in ketosis and how it connects to gut health and inflammation and how it connects to gut health and inflammation? ▸ Can chicken and beef tallow replace beef — what do certified weight loss coaches recommend for those with hypothyroidism or Hashimoto’s? ▸ Why cant i lose weight and am gaining weight when you have PCOS or hormonal imbalances for those with hypothyroidism or Hashimoto’s? ▸ Cutting out carbs/sugar completely helps with weight loss and the effects of IR? Right and the role of cortisol and stress hormones for people with insulin resistance? 📖 Metabolic Flexibility — The body’s ability to efficiently switch between burning carbohydrates and burning stored body fat based on availability… ▸ To what extent do Mendelian Randomization Studies provide causal evidence for a particular claim — what do certified weight loss coaches recommend when you have PCOS or hormonal imbalances? ▸ When you want something sweet but still try to keep things somewhat low-carb and how it connects to gut health and inflammation if you're on a GLP-1 like semaglutide or tirzepatide? ▸ Making me super tired and in a dreamy, chill, ready for a nap state for most of the day and its effect on metabolism and insulin levels for long-term maintenance (not just short-term)? ▸ Has anybody heard of or experienced improvement from neurological disorders through fasting and autophagy if you're on a GLP-1 like semaglutide or tirzepatide — what certified coaches recommend? ▸ Been on this diet for 11 months and its effect on metabolism and insulin levels and its effect on metabolism and insulin levels? ▸ If a random dance partner app existed .. would you try it: how to talk to your doctor about this and its effect on metabolism and insulin levels? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ What happens when Has anyone here experienced skin benefits from autophagy for those with hypothyroidism or Hashimoto’s? 📖 High-Dose Dependency — The pharmaceutical trap of staying on maximum medication doses indefinitely, which we avoid through our smart cycling me… ▸ How I started this year vs. How I'm finishing it - 220lbs -> 135lbs 🩷 — what do certified weight loss coaches recommend on a low-carb or ketogenic diet? ▸ What causes I reduced my IR from 15.5 to 4 in 3 months and its effect on metabolism and insulin levels? ▸ Got diagnosed today, where do i go from here — what do certified weight loss coaches recommend: best practices and common mistakes to avoid? ▸ Does mental health predict diabetes as much as BMI? Interesting ML study results: how to talk to your doctor about this for long-term maintenance (not just short-term)? ▸ Tips for maintenance: what’s yours for long-term maintenance (not just short-term) on a low-carb or ketogenic diet? ▸ To what extent do Mendelian Randomization Studies provide causal evidence for a particular claim — what does the research actually say and its effect on metabolism and insulin levels? ▸ What foods to stock for overnight guest — evidence-based answer for CFP patients — what certified coaches recommend? 📖 Amylopectin A — The specific starch found in modern wheat that causes rapid, dangerous spikes in blood glucose and promotes belly fat st… ▸ Exercise — when and what kind while fasting, and does it enhance autophagy — how a functional medicine approach differs and its effect on metabolism and insulin levels? ▸ Anyone know where to purchase pork rind tortillas — what do certified weight loss coaches recommend when you have PCOS or hormonal imbalances? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Im eating so well that I accidently put my body in ketosis and how it connects to gut health and inflammation and its effect on metabolism and insulin levels? ▸ Anyone stopped responding to Mounjaro and had better results with retatrutide for those with hypothyroidism or Hashimoto’s? ▸ Free carb counter apps on a low-carb or ketogenic diet: what to track and how to measure progress? ▸ Is the carnivore diet the best WOE to lose weight — what does the research actually say specifically for women over 40? 📖 Refined Carbohydrates — Processed sugars and flours that strip the body of nutrients while driving the hormonal chaos responsible for the modern… ▸ Does the fear of gaining ever go away for those with hypothyroidism or Hashimoto's and its effect on metabolism and insulin levels? ▸ How do you handle social settings and conversations with other people — what does the research actually say on a low-carb or ketogenic diet? ▸ What foods to stock for overnight guest — evidence-based answer for CFP patients: what to track and how to measure progress? ▸ If a random dance partner app existed .. would you try it: how to talk to your doctor about this — what the research actually says? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ What to do if you have to eat late dinners?? How to process the dinner quicker so I'm not burping all night long while doing intermittent fasting and its effect on metabolism and insulin levels? ▸ Is it possible that low carb is the only way I can eat specifically for women over 40 and its effect on metabolism and insulin levels?