Breakfast, a must for Individuals with Type 2 Diabetes Mellitus

What Happens when we Consume Food

After a meal, several important processes take place in response to increased nutrients and insulin secretion; these include β-Cell Responsiveness, Insulin Sensitivity, GLUT-4 Activity, and Muscular Glucose Uptake. Insulin secretion by pancreatic β-cells increases in response to elevated blood glucose levels (β- Cell Responsiveness). This helps regulate blood sugar and prevent excessive hyperglycemia.

Insulin binds to its receptor in skeletal muscle, activating the Akt/PKB pathway (Insulin Sensitivity). This leads to the translocation of GLUT4 glucose transporters from intracellular stores to the plasma membrane, enhancing glucose uptake by muscle cells [5]. GLUT4, an insulin- responsive glucose transporter, plays a crucial role (GLUT-4 Activity). It is expressed in adipose tissue, skeletal muscle, and cardiac muscle cells. Insulin-dependent glucose homeostasis relies on GLUT4 expression levels. Insulin action in muscle triggers the translocation of GLUT4 from intracellular compartments to the cell membrane, allowing increased glucose uptake by muscle cells (Muscular Glucose Uptake) [6]. These processes are enhanced during the early hours of the day, resulting in a better glycemic response to meals during the morning hours. The same carbohydrate content consumed in the evening would yield a lesser response. This highlights the importance of optimizing the morning hours to consume a good meal and the night hours (after sundown) for fasting and sleeping.

Internal Clocks and Meals – Working in Unison

We function upon the balance between two internal clocks. The Master clock is found in the hypothalamus in the suprachiasmatic nucleus (SCN), and the Peripheral clock is located in peripheral tissue. The clock genes located in SCN are synchronized by light signals, and the clock genes located in peripheral tissues are coordinated by signals coming from the SCN as well as the time and availability of food [7]. The initial exposure to daylight triggers the activation of the master circadian clock, which subsequently sends signals to peripheral clocks (Figure 1). When food is available during this early period, it aligns the central and peripheral clocks, leading to harmonious synchronization. Conversely, the absence of food during this time can result in misalignment. Notably, the first meal of the day, specifically breakfast, exerts a more potent resetting effect on the circadian network compared to other meals.

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Figure 1: Synchronization between central and peripheral clock genes. What Happens in Circadian Misalignment Chronic misalignment between circadian rhythms and daily behaviors occurs due to long-term changes in scheduling. This phenomenon is observed in shift workers, individuals who skip breakfast, consume late- night snacks, or engage in continuous snacking throughout the day.

complications [9].

T2D and the Circadian Clock

The dysregulation of the circadian clock plays a central role in the pathophysiology of type 2 diabetes (T2D). Reduced expression of clock genes in T2D is associated with insulin resistance, delayed β-cell secretion, decreased β-cell proliferation, postprandial hyperglycemia (PPHG), and elevated HbA1c levels. Notably, omitting breakfast in T2D patients exacerbates the disruption in clock gene expression, further contributing to PPHG and impaired early insulin and GLP-1 responses following subsequent meals. Additionally, T2D is characterized by declining β-cell function and deficient early postprandial insulin release. Therefore Breakfast is detrimental in a person with T2D [10, 11].

What do we eat in the Morning?

Now that it has been established that, eating in the morning and eating in line with your circadian rhythm is important, it is necessary to take a look at what should be consumed for breakfast.

Research has shown that consuming a higher energy content during the morning/day, compared to the evening/ night, can have several positive effects. These include resetting clock gene oscillations and promoting weight loss, reducing appetite, and improving postprandial hyperglycemia (PPHG) in individuals with type 2 diabetes [4]. This effect occurs independently of the total energy intake throughout the day. Therefore, starting the day with a hearty breakfast may have significant health benefits. Consuming a high-energy breakfast has a dual effect on circadian clock gene expression: it resets and synchronizes these genes. As a result, it enhances glucose metabolism, reduces postprandial glycemic excursions, and promotes weight loss in both individuals with type 2 diabetes and healthy individuals [12, 13].

A long-term study was carried out on patients with Type 2 Diabetes. Participants consumed either a whey protein breakfast diet, a high protein (Protein from sources other than whey) breakfast, or a carb-heavy breakfast. While both the protein-heavy breakfast meals displayed low postprandial hyperglycemia, the whey protein breakfast in T2D patients led to a greater reduction of HbA1C and body weight compared to the other two groups [14].