Some health experts believe that eating a large amount of fat and protein from animal sources, as allowed on the Atkins Diet, can increase your risk of heart disease or some cancers.
However, it’s not known what risks, if any, the Atkins Diet may pose over the long term because most of the studies about it have lasted for two years or less.
Mayo Clinic experts say most people can lose weight on almost any diet plan in the short term but studies show that long-term, low-carb diets like the Atkins Diet are no more effective for weight loss than are standard weight-loss diets
The Atkins Diet acknowledges that drastically cutting carbs in the early phase of the program can result in some side effects, including:
In addition, some very low carb diets restrict carbohydrates so much that they result in nutritional deficiencies or insufficient fibre, which can cause such health problems as constipation, diarrhoea and nausea.
Eating carbs that are high fibre, whole grain and nutrient dense can improve the health profile of programs like the Atkins Diet, though.
In addition, the Atkins Diet has changed over time to help prevent health problems, and it now recommends taking a small amount of extra salt, along with vitamins or supplements.
It’s also possible that restricting carbohydrates to less than 20 grams a day – the level recommended for phase 1 of the diet – can result in ketosis.
Ketosis occurs when you don’t have enough sugar (glucose) for energy, so your body breaks down stored fat, causing ketones to build up in your body. Side effects from ketosis can include nausea, headache, mental fatigue and bad breath.
In addition, the Atkins Diet isn’t appropriate for everyone. For example, the Atkins Diet recommends that you consult your doctor before starting the diet if you take diuretics, insulin or oral diabetes medications.
In addition, people with severe kidney disease should not follow the diet, and the weight-loss phases of the diet aren’t suitable for women who are pregnant or breast-feeding.
Source: Mayo Clinic