New Location is Now Open!

May 10, 2025

The Truth About Keto: Who It Works For & Who It Doesn’t

Back

The ketogenic (keto) diet—high fat, very low carb—has exploded in popularity for rapid weight loss and metabolic improvements. But is it the right choice for everyone? Let’s dive into the latest evidence and expert guidance to help you decide if keto belongs in your nutrition toolkit.

What Is the Ketogenic Diet?

Originally developed in the 1920s to treat epilepsy, keto drives your body into ketosis, a state where it burns fat (ketone bodies) instead of glucose for fuel SELF. Typical macronutrient targets:

  • 70–80% of calories from fat

  • 10–20% from protein

  • 5–10% from carbohydrates

Proven Benefits

  1. Rapid Weight Loss

    • A 2020 meta-analysis of 38 trials (6,499 participants) found low-carb diets led to modest weight loss (mean difference –1.3 kg) versus low-fat diets over 6–12 months FrontiersScienceDirect.

    • Early losses often reflect water weight, but many see reductions in body fat percentage as well.

  2. Metabolic & Blood-Sugar Improvements

    • Ketosis enhances insulin sensitivity. A recent umbrella review reports moderate-to-high quality evidence supporting keto’s benefits on glycemic control and lipid profiles in type 2 diabetes and obesity PMCEatingWell.

  3. Therapeutic Uses

    • Epilepsy Management: Keto remains a frontline therapy for drug-resistant epilepsy in children, cutting seizure frequency by over 50%.

    • Neurological Support: Emerging research explores benefits in Alzheimer’s and Parkinson’s disease, though long-term efficacy needs more study.

Limitations & Risks

  1. Sustainability Challenges

    • Most keto studies run ≤12 weeks; adherence often drops after 60 days due to dietary restrictiveness SELF.

    • Weight regain is common when returning to higher-carb eating.

  2. Nutrient Deficiencies

    • Cutting fruits, grains, and legumes can lower fiber, B vitamins, and phytonutrients—impacting gut health and bowel regularity.

    • A UK study found keto can reduce beneficial gut bacteria like Bifidobacteria, raising concerns about long-term gut integrity The Sun.

  3. Cardiovascular & Cholesterol Effects

    • In some individuals, LDL (“bad”) cholesterol spikes, potentially increasing heart-disease risk; monitoring lipids is essential .

  4. “Keto Flu” & Adaptation

    • Common early symptoms: fatigue, headaches, dizziness, and irritability as the body shifts fuel sources.

    • These typically resolve within 1–2 weeks with proper hydration, electrolyte balance, and gradual carb reduction.

Who Should Consider Keto?

  • Short-Term Weight Loss Goals: Under medical supervision, keto can kickstart fat loss for those with obesity or metabolic syndrome.

  • Neurological Conditions: It remains a validated therapy for epilepsy and is under investigation for other neurodegenerative disorders.

  • Metabolic Health Optimization: Clients with insulin resistance may benefit, but require close monitoring and reintroduction of carbs for long-term balance.

Not ideal for those with:

  • History of eating disorders

  • Uncontrolled lipid disorders without medical oversight

  • Certain digestive conditions (e.g., IBS) where fiber intake is critical

  • Advanced kidney or liver disease

Best Practices for Safe Implementation

  1. Medical Clearance & Monitoring

    • Always consult a healthcare provider before starting keto, especially if you have chronic health issues.

    • Regular blood tests to track lipids, liver and kidney function, and micronutrient levels.

  2. Prioritize “Clean Keto”

    • Focus on whole-food fat sources: avocados, nuts, seeds, olive oil, fatty fish.

    • Limit processed “dirty keto” foods (e.g., packaged meats, low-nutrient bars).

  3. Maintain Adequate Fiber

    • Incorporate low-carb, high-fiber veggies: leafy greens, broccoli, cauliflower, and flaxseed.

    • Consider a psyllium supplement if needed to support digestion.

  4. Strategic Carb Refeeds

    • Implement cyclical keto: higher-carb days (e.g., weekends) to refill muscle glycogen and support thyroid function.

    • Use carb refeeds around high-intensity training sessions for performance.

  5. Combine with Resistance & Functional Training

    • Pairing keto with strength training helps preserve lean muscle and maintain metabolic rate.

    • Our trainers in Mount Sinai & Stony Brook integrate targeted workouts to maximize body-composition improvements.

Ready to Optimize Your Nutrition?
Whether you’re curious about keto or seeking a balanced, long-term eating plan, our registered dietitians and nutrition coaches in Mount Sinai & Stony Brook can guide you.
👉 Book a Nutrition Consultation and get a customized, science-based program tailored to your goals.