Yeah it is odd. They should have funded a study claiming that high fat low carb diets are healthy, since those who eat that way are forever stuck in "Stall City" aka "Dad Bod City"
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I'm yet to see a drug free guy who follows a keto or carnivore diet with a small waist. They're all storing fat over their lower abs due to high cortisol and love handles due to insulin resistance.
The women who follow high carb/low fat diets also have less fat around their waists than those who follow high fat/low carb diets.
When I tried a high fat/low fat diet I had ED for the first time in my life and my TSH went from 1.1 to 2.5
Cole Robinson has had hundreds of guys come to him who ended up with such suppressed testosterone from following a high fat/low carb diet that they had to go on TRT!
Repeating things over and over doesn’t make them true.
Weight Loss on High-Carb, Low-Fat vs. Low-Carb, High-Fat Diets:
• Evidence: Studies show both high-carb, low-fat (HCLF) and low-carb, high-fat (LCHF) diets can lead to weight loss, with effectiveness depending on adherence, calorie balance, and individual metabolic differences. A 2018 meta-analysis in The Lancet found no significant difference in weight loss between low-carb and low-fat diets when calories are controlled (DOI: 10.1016/S2213-8587(18)30135-8). However, some individuals may find HCLF diets easier to sustain due to food availability or preferences, while others thrive on LCHF diets due to appetite suppression from higher fat and protein.
• Verdict: The claim that the “vast majority” lose more weight on HCLF is not universally supported. Weight loss outcomes vary widely based on individual factors like genetics, activity levels, and adherence.
2. Energy, Libido, Sexual Function, Muscle Strength, Endurance, Mood, and Mental Clarity:
• Energy: HCLF diets may provide quick energy from glucose, which can benefit high-intensity exercise or those adapted to carb-based metabolism. LCHF diets may lead to stable energy via ketosis but can cause fatigue during the initial adaptation phase (1-4 weeks). Long-term, energy levels depend on nutrient balance and individual response.
• Libido/Sexual Function: No robust evidence directly links HCLF diets to better sexual function across populations. Testosterone levels, which influence libido, can be affected by diet, but studies (e.g., Journal of Steroid Biochemistry and Molecular Biology, 2016) suggest adequate fat intake is crucial for hormone production. Very low-fat diets may reduce testosterone in some cases.
• Muscle Strength/Endurance: HCLF diets may support endurance activities due to glycogen availability, but LCHF diets can preserve muscle mass if protein intake is adequate (e.g., Journal of the International Society of Sports Nutrition, 2017). Strength gains depend more on training and protein than carb-to-fat ratios.
• Mood/Mental Clarity: Carbs can boost serotonin via insulin-mediated tryptophan uptake, but evidence linking LCHF diets to depression is mixed. Some studies (e.g., Frontiers in Psychiatry, 2021) suggest ketogenic diets may improve mood in certain populations by stabilizing blood sugar or reducing inflammation. Mental clarity on LCHF diets is often reported anecdotally during ketosis but varies.
• Verdict: These benefits are highly individual. HCLF diets may suit some for energy and mood, but LCHF diets can also support these outcomes once adapted. No universal superiority exists.
3. Depression and Serotonin Suppression on LCHF Diets:
• Evidence: Serotonin production relies on tryptophan, which is influenced by insulin from carbs. However, LCHF diets don’t inherently suppress serotonin to the point of causing depression in most people. A 2020 review in Nutritional Neuroscience found no consistent link between LCHF diets and worsened mood; some studies even suggest benefits for anxiety or depression in specific cases. Individual factors like gut health or micronutrient status play a role.
• Verdict: The claim that LCHF diets commonly cause depression via serotonin suppression is speculative and not well-supported. Mood effects vary widely.
4. Thyroid Function and TRT/Thyroid Meds:
• Thyroid Function: LCHF diets, especially very low-carb ketogenic diets, can lower T3 levels (active thyroid hormone) in some individuals, as seen in studies like Thyroid (2013, DOI: 10.1089/thy.2013.0105). This is often a physiological adaptation to conserve energy, not necessarily dysfunction requiring medication. HCLF diets may maintain higher T3 levels due to insulin’s role in thyroid hormone conversion, but clinical hypothyroidism from LCHF is rare in healthy individuals.
• TRT (Testosterone Replacement Therapy): No strong evidence links LCHF diets directly to the need for TRT. Very low-fat diets may reduce testosterone more than moderate-fat LCHF diets, as fats are critical for steroid hormone synthesis. Extreme caloric deficits or nutrient deficiencies in any diet can disrupt hormones.
• Verdict: The claim about thyroid dysfunction and TRT is exaggerated. LCHF diets may alter thyroid markers in some, but medication is rarely needed unless pre-existing conditions exist. HCLF diets aren’t inherently protective.
Overall: The statement is partially true for some individuals but overgeneralizes. HCLF diets may benefit certain people for energy, mood, or performance, but LCHF diets are equally effective for others, especially for weight loss or metabolic health (e.g., improved insulin sensitivity). Claims about depression, serotonin, thyroid issues, and TRT lack robust evidence and ignore individual variability. Diet success depends on personalization, adherence, and overall nutrient quality.
