Keto Myths Debunked — What NZ Kiwis Still Get Wrong

Lifestyle | 8 min read

Keto has been mainstream in New Zealand for years now, yet the same handful of myths keep circulating at barbecues, in Facebook groups, and from well-meaning family members. Some of these myths are outdated. Others contain a grain of truth that gets exaggerated along the way. Here is what the actual evidence says about six of the most persistent ones.

Myth 1: Keto destroys your cholesterol

This one deserves a genuinely nuanced answer rather than a flat yes or no. On keto, HDL cholesterol, the beneficial kind, typically rises, and triglycerides usually fall. However, a large 2023 umbrella review of clinical trials found keto is also linked to a real, meaningful increase in LDL cholesterol for some people. This effect appears strongest in lean, active individuals, sometimes called “lean mass hyper-responders,” and can vary significantly depending on how much saturated fat the diet includes. This is not a myth to wave away. It is worth getting your cholesterol checked periodically on keto, particularly if you have a family history of heart disease.

Myth 2: Keto damages healthy kidneys

This myth traces back to an old assumption that higher protein intake overworks the kidneys. Multiple studies spanning three to twelve months have found no evidence of harm to kidney function in people with healthy kidneys. One study even followed people with type 1 diabetes on keto for ten years and found no negative effect on kidney function. The genuine caveat sits with people who already have kidney disease, where a ketogenic diet’s higher fat and protein content warrants real caution and closer medical supervision, not a blanket restart.

Myth 3: You can eat unlimited bacon, cheese, and cream

This is one of the more damaging myths, because it turns keto into an excuse for poor food quality rather than a genuine way of eating well. A well-formulated keto diet centres on vegetables, quality protein, and healthy fats. It is not a free pass to eat processed meat and cheese without limit. People who follow the “bacon and butter” version of keto often see worse cholesterol outcomes than those building meals around whole foods, which lines up with the cholesterol research above.

Myth 4: Keto causes muscle loss

This myth assumes the body cannot get enough protein without carbohydrate, which is not accurate. Muscle is built and maintained through adequate protein intake and resistance training, both of which are entirely compatible with keto. Research on trained athletes following keto for several months has found muscle mass maintained when protein intake stays adequate. The real risk factor is protein, not carbohydrate restriction itself.

Myth 5: Keto is unsustainable long term

This one is true for some people and false for others, which is exactly why it persists. Keto fails long term most often when it feels restrictive or repetitive, not because of any built-in expiry date. People who build variety into their meals, plan for social situations, and keep flavour genuinely enjoyable tend to sustain it for years.

Myth 6: All fruit is completely off-limits

Keto rules out high-sugar fruit like bananas and grapes, but plenty of low-carb fruit fits comfortably into a keto day. Berries in particular carry meaningful fibre alongside their natural sugar, and a small serve of raspberries or strawberries fits most people’s daily carb allowance without issue. The real rule is portion and fruit choice, not a total ban.

The bottom line

Most keto myths contain a small kernel of truth stretched well past what the evidence actually supports. Cholesterol and kidney health genuinely deserve monitoring, particularly for certain individuals, rather than blanket dismissal or blanket fear. Meanwhile, claims about unlimited processed food, guaranteed muscle loss, and complete fruit bans do not hold up against the research. Understanding the difference helps you build a keto approach based on evidence, not internet folklore.

Sources: peer-reviewed umbrella reviews and clinical studies on ketogenic diets, cholesterol, kidney function, and muscle mass, published via PubMed/PMC. This article is for general information only and does not replace advice from your healthcare provider.