Diabetic patients are, generally, recommended to follow a diet that is low in fat and high in carbohydrates [1] . Clinical studies, conversely, showed metabolic benefits conferred by carbohydrate-restricted diets including the ketogenic diet [2] [3] and the paleolithic diet [4] [5] in type 2 diabetes. Much less data on the use of low carbohydrate diets in type 1 diabetes (T1DM) are available. Two studies by Nielsen et al. showed that a low carbohydrate diet lowers the need for insulin as well as the number of hypoglycemic episodes in T1DM [6] [7] . It was also suggested that a low carbohydrate diet is sustainable on the long-term [6] [7] . Ketogenic diets have long been used in epilepsy [8] . There are three cases in literature, where concurrent epilepsy and T1DM were treated with the classical ketogenic diet and both conditions improved [9] [10] [11] . Recently, we published a case of childhood absence epilepsy where seizure freedom was achieved using a modified ketogenic diet we refer to as the paleolithic-ketogenic diet [12] . Herein, we present a case of T1DM, where the same diet resulted in remission of T1DM as assessed by normalization of blood glucose levels and elevation in C-peptide level allowing for discontinuation of external insulin replacement.

A 19-year-old male complained of increased thirst, polyuria, itchy skin, malaise, and weight loss. The symptoms were present for about two weeks prior to diagnosis. On November 24, 2013 self monitoring of blood glucose showed 384 mg/dL. Previous medical history was unremarkable. Anamnestic data included consuming of muscle boosting protein through a month prior to symptom onset. Laboratory assessment on November 25, 2013 (Table 1) showed elevations in glucose (218 mg/dL) and HbA1c (9.2%). Testing for glutamic acid decarboxylase (GAD) antibodies showed positivity (52 U/mL; normal range 0–10 U/mL) and mild positivity for pancreatic islet cell autoantibodies (ICAs). C-peptide level was not measured at this time. He was diagnosed with T1DM. He was put on insulin replacement therapy (38 IU of insulin) and standard conventional diabetes diet with six meals containing 240 grams carbohydrate daily. He followed this regime for 20 days. While on this regime his glucose levels fluctuated between 68–267 mg/dL (Figure 1). Carbohydrate he consuming before was less than 240 grams. Since his malaise did not improve the patient consulted the first author in December 2013. To ascertain T1DM laboratory examination of C-peptide was carried out. C-peptide level of 0.6 ng/mL measured on January 08, 2014 indicated subnormal insulin secretion (Figure 2). The patient was suggested to switch to the paleolithic-ketogenic diet which he initiated on December 21, 2013. From this time, he was also taking 5,000 IU of vitamin D3 but nothing else as supplement. His diet consisted of meat, organ meat, fat and eggs. In his diet, red and fat meats dominated over lean meats. He was eating vegetables in insignificant amounts. His diet had a ketogenic ratio (fat : protein + carbohydrate) of at least 2:1. No oil of plant origin or artificial sweeteners were allowed. The patient was under our close control and reported daily food records and blood glucose levels. Upon shifting toward the paleolithic ketogenic diet glucose levels returned to normal and no major elevations were seen postprandially either. Insulin was therefore discontinued. The tapering of insulin was done promptly: following the first paleolithic-ketogenic meal glucose level was only 86 mg/dL thus there was no need for external insulin. Similar blood glucose levels were measured on subsequent meals on the diet. Thus, the patient required no insulin subsequently either. Home glucose monitoring was carried out preprandially as well as postprandially and tracked once a day for consecutive meals (that is on consecutive days measures were taken for breakfast, lunch and dinner, respectively). Average blood glucose level while on the standard diabetes diet with insulin was 119 mg/dL while 85 mg/dL on the paleolithic-ketogenic diet without insulin. Fluctuations in glucose levels decreased as indicated by a reduction of standard deviation values from 47 mg/dL on the standard diabetes diet to 9 mg/dL on the paleolithic-ketogenic diet. Average postprandial glucose elevation on the standard diabetes diet was 23 mg/dL while only 5.4 mg/dL on the paleolithic-ketogenic diet (Figure 1). C-peptide measurement was repeated on the 10th week of the diet (on March 06, 2014). This indicated an elevation to a value of 2.2 ng/mL (Figure 2). A comprehensive laboratory workup carried out on March 14, 2014 indicated normal laboratory parameters with the exception of total cholesterol and LDL cholesterol which were slightly elevated. Glucose level was 88 mg/dL while HbA1c was 5.5% (for all laboratory values see Table 1). Urinary ketone was positive. On March 21, 2014 antibody testing for ICA showed no change in the mild positivity measured before and some elevation in GAD antibodies (86 U/mL). At the time of writing this case report, the patient is on the paleolithic ketogenic diet for 6.5 months and still exhibit low glucose levels. No side effects emerged and he is completely free of symptoms. The patient gave written informed consent for writing this case study.