5 Foods to Avoid at All Costs
Achieving and maintaining ketosis isn’t just about what you eat—it’s also about what you avoid. Certain foods can derail your ketogenic progress, hinder fat loss, and harm your overall health. Let’s dive into the scientific reasons why these five common culprits can disrupt your keto journey and make weight loss harder.
1. MSG: The Hidden Appetite Stimulant
Why It’s Harmful:
Monosodium glutamate (MSG) is a flavour enhancer that stimulates your taste buds, making food more addictive. MSG interferes with leptin, the hormone responsible for signaling fullness, which can lead to overeating. This is particularly problematic for weight loss, as it encourages calorie overconsumption.
How It Affects Keto:
- MSG may increase insulin spikes in some people, promoting fat storage instead of fat burning.
- It triggers cravings, often for high-carb, ultra-processed foods that can take you out of ketosis.
Scientific Insight:
A 2011 study in Obesity found that higher MSG consumption is linked to an increased risk of obesity due to its effect on appetite control.
2. Sugar: The Ultimate Keto Disruptor
Why It’s Harmful:
Sugar is the primary fuel for glucose metabolism, which your body relies on before switching to fat-burning in ketosis. Even small amounts of sugar can raise blood sugar and insulin levels, halting ketone production and promoting fat storage. Additionally, frequent sugar consumption leads to insulin resistance, a condition where your body struggles to metabolise sugar efficiently.
How It Affects Keto:
- Sugar spikes insulin, a hormone that blocks fat burning.
- High sugar intake creates an energy rollercoaster, causing cravings and overeating.
Scientific Insight:
Studies show that sugar promotes inflammation, which not only slows weight loss but also contributes to chronic diseases like diabetes and heart disease. A 2017 review in Diabetes Care found strong links between sugar consumption and insulin resistance, a key driver of weight gain.
3. Grains: Carbs in Disguise
Why They’re Harmful:
Grains, even whole grains, break down into glucose during digestion, raising blood sugar and insulin levels. They also contain anti-nutrients like phytic acid, which can interfere with nutrient absorption. For many people, gluten—a protein found in wheat—causes gut inflammation, which can impair metabolic health and hinder weight loss.
How They Affect Keto:
- Grains are carbohydrate-dense, making it nearly impossible to stay within the keto carb limit (5-10% of total calories).
- Inflammation caused by gluten can elevate cortisol, a stress hormone that promotes fat storage.
Scientific Insight:
A 2020 study in Nutrients showed that diets high in refined grains are associated with higher visceral fat accumulation, a dangerous type of fat linked to metabolic disorders.
4. Dairy: The Inflammation Trigger
Why It’s Harmful:
Many dairy products, especially processed ones, can be inflammatory. Casein, a protein found in dairy, is difficult for some people to digest, leading to bloating and gut irritation. Dairy also contains natural sugars (lactose), which can impact blood sugar levels. Overconsuming dairy can lead to calorie overload without providing satiety, especially if eaten in large quantities.
How It Affects Keto:
- Overeating dairy, particularly cheese, adds hidden carbs and calories that can stall fat loss.
- Inflammatory responses to dairy can disrupt metabolic function and impair ketone production.
Scientific Insight:
A 2018 study in Frontiers in Immunology linked dairy intolerance to systemic inflammation, which has been shown to negatively impact weight loss and metabolic health.
5. Alcohol: A Fat-Burning Blocker
Why It’s Harmful:
When you consume alcohol, your liver prioritises detoxifying the alcohol over other metabolic functions, including producing ketones. Alcohol also disrupts hormonal balance, increasing cortisol and lowering testosterone, both of which are critical for fat-burning and muscle maintenance.
How It Affects Keto:
- Delays ketosis by halting ketone production while the liver processes alcohol.
- Can trigger carb cravings and lead to poor food choices.
Scientific Insight:
Research published in The American Journal of Clinical Nutrition shows that alcohol consumption reduces fat oxidation (fat burning) and increases the risk of weight gain when consumed regularly.
The Bottom Line: Why These Foods Derail Keto and Weight Loss
- MSG: Triggers cravings and appetite, making it harder to control calorie intake.
- Sugar: Spikes insulin, blocks fat burning, and fuels inflammation.
- Grains: High-carb, nutrient-blocking, and inflammatory, they keep your body in glucose-burning mode.
- Dairy: Can be inflammatory, calorie-dense, and disrupt metabolic processes if overconsumed.
- Alcohol: Stops fat-burning in its tracks and disrupts hormone balance.
By eliminating these foods, you’ll not only maintain ketosis but also optimise your body’s ability to burn fat, reduce inflammation, and improve overall health.
Ready to optimise your keto journey? Check out our Keto Diet Guide for meal plans, tips, and tools to keep you on track and achieve your weight loss goals.
