Till a few years back, type 2 diabetes was regarded as an irreversible and progressive condition. But now there is evidence to show that the underlying pathogenetic processes in type 2 diabetes are potentially reversible and this can be achieved by cutting down on the intake of dietary calories, which normalised beta cell function and also the hepatic insulin sensitivity thus decreasing  hepatic glucose production. This is also as per the twin cycle hypothesis of etiology of type 2 diabetes, which postulated that type 2 diabetes is caused by accumulation of excess fat within the liver and pancreas.

The UK Primary Care Diabetes Society and Association of British Clinical have defined three criteria for remission of type 2 diabetes: weight loss, fasting plasma glucose < 126 mg/dL (7 mmol/L) or HbA1c 6.5% (<48 mmol/mol) (WHO diagnostic thresholds) on two occasions separated by at least six months and attainment of these glycemic parameters after totally stopping all anti-diabetic medications.

The twin cycle hypothesis was tested in the Counterpoint study published in 2011, which confirmed that intake of a very low calorie diet normalised the liver fat within a week and also pancreatic fat accumulation in 8 weeks leading to normal plasma glucose control. People with type 2 diabetes achieved an average of over 15 kg weight loss over a period of 8 weeks during normal living.

The Counterbalance (Counteracting BetA cell failure by Long term Action to Normalize Calorie intakE) study published in 2016 further showed that this normalisation of liver and pancreas fat was durable provided there was no further weight gain.

Do low calorie diets benefit? A low fat diet is usually advised for weight loss. However, carbohydrates as substitute to saturated fats are also not the answer. Increased consumption of carbohydrates increases total and “bad” LDL cholesterol and reduces the “good” HDL) cholesterol. Studies have shown that both low calorie and low carbohydrate diets can be effective for weight loss if participants can adhere to the diet. More than the amount of total fats consumed, it is the type of fat that is important. Saturated and trans fats increase LDL cholesterol and decrease the HDL cholesterol. Replace saturated and trans fats in diet with mono- and polyunsaturated fats. Similar is the case for carbohydrates. Randomly reducing carbohydrates in diet would make one lose out on the benefits of complex carbohydrates in fiber and whole grains.

Portion control is another established dietary strategy for weight loss. Eating small portions can help.

It has been speculated that advice on foods within an overall dietary pattern attains better longer term adherence to the diet prescribed. The health benefits of Mediterranean diet, DASH diet are well established.

Type 2 diabetes is a potentially reversible condition. Early weight loss after diagnosis facilitates remission of type 2 diabetes. Several strategies have been suggested for weight loss and the durability of the weight loss, which can be individualised together with increased physical activity. In a nutshell, healthier food choices i.e. avoiding processed and ultraprocessed foods and eating more of fresh, whole foods have health benefits besides weight control as well as glycemic control. This can be further aided by policies such as increasing taxes on calorie dense foods such as sugar-sweetened beverages and reducing the trans fat content of foods. India has set a target of reducing trans fats in diet to ≤2% by January 2022. The World Health Organisation (WHO) has set a target to be trans fat-free by 2023.

(Source: Taylor R, et al. Nutritional basis of type 2 diabetes remission. BMJ. 2021 Jul 7;374:n1449. doi: 10.1136/bmj.n1449)